The enthalpy for a two-step reaction, given for the two steps are 225 KJ and -147 KJ, respectively is found to be 78 kJ.
To find the enthalpy of the overall reaction, we need to add the enthalpies of the two steps. If the reaction is,
A → B → C, the reactant A, intermediate is B, and the final product is C, then we can write the enthalpy change for the two steps as,
ΔH₁: A → B, enthalpy change = 225 kJ
ΔH₂: B → C, enthalpy change = -147 kJ
The overall enthalpy change for the reaction A → C is the sum of the enthalpies for the two steps, so,
ΔHtotal = ΔH₁ + ΔH₂
= 225 kJ + (-147 kJ)
= 78 kJ
Therefore, the enthalpy change for the overall reaction A → C is 78 kJ.
To know more about enthalpy of reaction, visit,
https://brainly.com/question/28772375
#SPJ4
after how many years will the activity of a new sample of cobalt 60 be decreased to 1 8 its original value?
After 15.81 years will the activity of a new sample of cobalt 60 be decreased to 1/8 its original value.
Cobalt-60 has a half-life of roughly 5.27 years, which indicates that a sample's activity is reduced by half every 5.27 years. We may use the following formula to calculate how long it will take for the activity of a new sample of cobalt-60 to decline to 1/8 of its initial value.
t = t1/2 x log₂(Nf / Ni), time it takes for the activity to decrease is t, the half-life of cobalt-60 (5.27 years) is t1/2, the final activity (1/8 of the initial activity) Nf, and initial activity (1) is Ni. Plugging in the values, we get,
t = 5.27 years x log₂(1/8)
t = 5.27 years x log₂0.125
t = 5.27 years x (-3)
t = -15.81 years
The negative result here does not make sense because time cannot be negative. Therefore, we need to take the absolute value of the result, which gives,
t = 15.81 years
Thus, it will take approximately 15.81 years for the activity of a new sample of cobalt-60 to decrease to 1/8 its original value.
To know more about radioactivity, visit,
https://brainly.com/question/1236735
#SPJ4
Complete question - After how many years will the activity of a new sample of cobalt 60 be decreased to 1/8 its original value?
22 g of KCl and 200 g of H,O Express your answer using two significant figures. AEP O ? Submit Request Answer Part B 11 g of sugar in 225 g of tea with sugar (solution) Express your answer using two significant figures. 0 AED ON? Submit Request Answer Part 7.0 g of CaCl, in 85.0 g of CaCl, solution Express your answer using two significant figures 90 AED ROO? MacBook Air
A. The answer is 4.9 % (2 sig figs). This gives us 0.115 mol of KCl and 0.0938 mol of H₂O.
B. The answer to this question is 4.9 % (2 sig figs). This gives us 0.068 mol of sugar and 0.0938 mol of tea.
What is molar mass?It is calculated by adding together the atomic masses of all the atoms in the substance. The molar mass of a substance is an important factor for understanding its properties and behavior.
Part A: 22 g of KCl and 200 g of H₂O.
The answer to this question is 4.9 % (2 sig figs). This can be calculated by first converting the given masses of KCl and H₂O into moles, using their respective molar masses.
This gives us 0.115 mol of KCl and 0.0938 mol of H₂O.
We can then calculate the mass percent of KCl in the solution by dividing the mass of KCl by the total mass of the solution and multiplying by 100. This gives us 4.9 % (2 sig figs) of KCl in the solution.
Part B: 11 g of sugar in 225 g of tea with sugar (solution).
The answer to this question is 4.9 % (2 sig figs). This can be calculated by first converting the given masses of sugar and tea into moles, using their respective molar masses.
This gives us 0.068 mol of sugar and 0.0938 mol of tea.
We can then calculate the mass percent of sugar in the solution by dividing the mass of sugar by the total mass of the solution and multiplying by 100.
This gives us 4.9
For more questions related to atomic masses
https://brainly.com/question/30390726
#SPJ1
A. The answer is 4.9 % (2 sig figs). This gives us 0.115 mol of KCl and 0.0938 mol of H₂O.
B. The answer to this question is 4.9 % (2 sig figs). This gives us 0.068 mol of sugar and 0.0938 mol of tea.
What is molar mass?It is calculated by adding together the atomic masses of all the atoms in the substance. The molar mass of a substance is an important factor for understanding its properties and behavior.
Part A: 22 g of KCl and 200 g of H₂O.
The answer to this question is 4.9 % (2 sig figs). This can be calculated by first converting the given masses of KCl and H₂O into moles, using their respective molar masses.
This gives us 0.115 mol of KCl and 0.0938 mol of H₂O.
We can then calculate the mass percent of KCl in the solution by dividing the mass of KCl by the total mass of the solution and multiplying by 100. This gives us 4.9 % (2 sig figs) of KCl in the solution.
Part B: 11 g of sugar in 225 g of tea with sugar (solution).
The answer to this question is 4.9 % (2 sig figs). This can be calculated by first converting the given masses of sugar and tea into moles, using their respective molar masses.
This gives us 0.068 mol of sugar and 0.0938 mol of tea.
We can then calculate the mass percent of sugar in the solution by dividing the mass of sugar by the total mass of the solution and multiplying by 100.
This gives us 4.9
For more questions related to atomic masses
https://brainly.com/question/30390726
#SPJ1
What volume (in L) of 1.60 M Na3PO, would be required to obtain 0.600 moles of Nations?
To make 0.600 moles of PO43-, you would need 0.375 L of 1.60 M Na₃PO₄.
How is 0.1 M AgNO₃ solution calculated?By mixing 1.7 g of silver nitrate with 100 ml of water, you can create a stock solution of 0.1 M silver nitrate. Prior to making the Silver thiosulphate solution (STS), store the stock solutions in the dark. The (STS) is typically made using a 1:4 molar ratio of silver to thiosulphate.
For the reaction between Na₃PO₄ and water, the balanced chemical equation is:
Na₃PO₄ + 3 H₂O → 3 Na₊ + PO₄₃₋ + 3 OH₋
We can observe from this equation that 1 mole of Na₃PO₄ results in 1 mole of PO₄₋ ions. We would require 0.600 moles of Na₃PO₄ in order to produce 0.600 moles of PO₄₃₋.
The needed volume of 1.60 M Na₃PO₄ can be determined using the following formula:
Volume (L) = moles / molarity
Volume = 0.600 moles / 1.60 M
Volume = 0.375 L
To know more about solution visit:-
https://brainly.com/question/30665317
#SPJ1
At 25 Celsius does hydrogen or nitrogen have the higher average kinetic energy?
Answer:
Yes
Explanation:
17×10−21 J/molecule.
Spacecraft bring back samples of two asteroids. One brings back a small sample, and the other brings back a large sample. Back on Earth, scientists observer that the samples have a similar color and hardness. Scientists weigh the samples and find that the small sample has a mass of 10 grams, and the large sample has a mass of 1,000 grams.
Write a set of procedures that will allow any scientist to be able to gather more evidence about whether the two samples are likely to be the same substance or not.
This is just confusing.
Here are some procedures that scientists can follow to gather more evidence about whether samples are the same substance or not: Conduct a chemical analysis, Conduct a spectroscopic analysis, Conduct a crystallographic analysis, Conduct a density analysis
Conduct a chemical analysis: If the samples have the same composition, then they are likely to be the same substance.
Conduct a spectroscopic analysis: If the spectral signatures are the same, then the samples are likely to be the same substance.
Conduct a crystallographic analysis: If the crystal structures are the same, then the samples are likely to be the same substance.
Conduct a density analysis: If the densities are the same, then the samples are likely to be the same substance.
To know more about spectral signatures, here
brainly.com/question/22636286
#SPJ1
moving from less condensed phases to more condensed phases is an exothermic process, and the reverse is an endothermic process. group of answer choicestruefalse
It is True. Moving from less condensed phases (such as gas) to more condensed phases (such as liquid or solid) involves particles coming closer together and releasing energy, which makes it an exothermic process.
The reverse, going from more condensed phases to less condensed phases, requires energy input to overcome the intermolecular forces holding the particles together, making it an endothermic process. Exothermic processes are those that release energy, while endothermic processes are those that absorb energy. In this context, when a substance moves from a less condensed phase to a more condensed phase, energy is released in the form of heat. The reverse process, moving from a more condensed phase to a less condensed phase, requires energy and thus is endothermic.
To learn more about exothermic process click here https://brainly.com/question/12321421
#SPJ11
The ΔH∘vap of a certain compound is 29.93 kJ⋅mol−1 and its Δvap∘ is 83.12 J⋅mol−1⋅K−1.What is the normal boiling point of this compound?
The normal boiling point of the compound is approximately 450.4K
How to calculate the boiling point of a compound?The normal boiling point of a substance is the temperature at which its vapor pressure is equal to 1 atmosphere (atm). We can use the Clausius-Clapeyron equation to calculate the normal boiling point of the compound using the given information:
ln(P1/P2) = (-ΔHvap/R) * (1/T1 - 1/T2)
where P1 and P2 are the vapor pressures of the compound at temperatures T1 (normal boiling point) and T2 (known temperature), respectively, ΔHvap is the enthalpy of vaporization, R is the ideal gas constant (8.314 J/(mol*K)), and T1 and T2 are temperatures in Kelvin (K).
Given:
ΔHvap = 29.93 kJ/mol = 29.93 * 10^3 J/mol
ΔSvap = 83.12 J/(molK)
R = 8.314 J/(molK)
Plugging in the values:
ln(P1/1 atm) = (-29.93 * 10^3 J/mol)/(8.314 J/(molK) * T1) - (83.12 J/(molK)/T1)
Solving for Tb, we get:
Tb = (-ΔH∘vap/R) * (1/(ln(Pvap/1 atm)) + 1/Tref)
Substituting the given values, we get:
Tb = (-29.93 kJ⋅mol−1 / (8.314 J⋅mol−1⋅K−1)) * (1/(ln(Pvap/1 atm)) + 1/298 K)
Plugging in the values:
ln(P1/1 atm) = (-29.93 * 10^3 J/mol)/(8.314 J/(molK) * T1) - (83.12 J/(molK)/T1)
At the normal boiling point, the vapor pressure is 1 atm, so P1 = 1 atm.
Therefore, the normal boiling point of the compound is:
Tb = (-3602.2 K) * (1/(ln(1/1)) + 0.0033557)
Tb = 450.4 K
To know more about Clausius-Clapeyron equation:
https://brainly.com/question/15164257
#SPJ11
calculate the solubility of iron(ii) hydroxide (ksp=4.87×10−17)(ksp=4.87×10−17) in pure water in grams per 100.0 mlml of solution.
The solubility product expression for iron(II) hydroxide, Fe(OH)2, is:
Ksp = [Fe2+][OH-]^2 = 4.87×10^-17
Let's assume that the initial concentration of Fe2+ and OH- ions in pure water is x M. Then, the equilibrium concentration of Fe2+ and OH- ions will also be x M.
Therefore, the solubility product expression becomes:
Ksp = x * (2x)^2 = 4x^3
Solving for x:
4x^3 = 4.87×10^-17
x^3 = 1.2175×10^-17
x = (1.2175×10^-17)^(1/3)
x = 2.312×10^-6 M
The solubility of Fe(OH)2 is equal to the concentration of Fe2+ ions, which is x.
To convert this to grams per 100.0 ml of solution, we need to multiply by the molar mass of Fe(OH)2 and the volume of the solution:
solubility = x * molar mass * 100 / volume
Assuming the molar mass of Fe(OH)2 is 89.86 g/mol and the volume of the solution is 100.0 ml, we get:
solubility = (2.312×10^-6 M) * (89.86 g/mol) * 100 / 100.0 ml
solubility = 0.00208 g/100.0 ml
Therefore, the solubility of iron(II) hydroxide in pure water is 0.00208 g/100.0 ml of solution.
*IG:whis.sama_ent*
When 2.65 g of an unknown weak acid (HA) with a molar mass of 85.0 g/mol is dissolved in 250.0 g of water, the freezing point of the resulting solution is -0.259 ?C. Part A Calculate Ka for the unknown weak acid.
When 2.65 g of an unknown weak acid (HA) with a molar mass of 85.0 g/mol is dissolved in 250.0 g of water, the Kₐ for the unknown weak acid is 2.367 × 10⁻⁴
We know that,
dT = Kf ×molality × i
= Kf×m×i
"i" is the van't Hoff factor.
Molality is defined as the number of moles of solute divided by the mass of solvent in kg.
i.e. molality
= (no of moles of solute) / Kg of solvent
= 2.65g /250g x 1 mol /85 g x1000g/kg
=0.1247 moles
and Kf for water = - 1.86 and dT = -0.259
by substitution
0.259 = 1.86× 0.1247 × i
Therefore, i = 1.116
when the degree of dissociation formula is:
when n=2 and i = 1.116
a= i-1/n-1
= (1.116 -1)/(2-1)
= 0.116
Substituting these values to find Kₐ
∴K = Ca^2/(1-a)
= (0.1247 × 0.116)² / (1-0.116)
= 2.367 × 10⁻⁴
To know more about Kₐ here
https://brainly.com/question/9173788
#SPJ4
If 30.10 mL of NaOH were required to titrate 10.00 mL of 0.2341 M H2SO4, what is the molarity of the NaOH solution?
The molarity of the NaOH solution is 0.1554 M. To get the molarity of the NaOH solution used to titrate 10.00 mL of 0.2341 M H2SO4 with 30.10 mL of NaOH, follow these steps:
Step:1. Write the balanced chemical equation for the reaction: H2SO4 + 2NaOH → Na2SO4 + 2H2O
Step:2. Calculate the moles of H2SO4: moles = Molarity × Volume = 0.2341 M × 0.010 L = 0.002341 moles
Step:3. Determine the stoichiometric ratio between H2SO4 and NaOH: 1:2 (1 mole of H2SO4 reacts with 2 moles of NaOH)
Step:4. Calculate the moles of NaOH required: 0.002341 moles H2SO4 × (2 moles NaOH / 1 mole H2SO4) = 0.004682 moles NaOH
Step:5. Determine the molarity of the NaOH solution: Molarity = moles / Volume = 0.004682 moles / 0.0301 L = 0.1554 M. So, the molarity of the NaOH solution is 0.1554 M.
Learn more about molarity here, https://brainly.com/question/14469428
#SPJ11
The molarity of the NaOH solution is 0.1554 M. To get the molarity of the NaOH solution used to titrate 10.00 mL of 0.2341 M H2SO4 with 30.10 mL of NaOH, follow these steps:
Step:1. Write the balanced chemical equation for the reaction: H2SO4 + 2NaOH → Na2SO4 + 2H2O
Step:2. Calculate the moles of H2SO4: moles = Molarity × Volume = 0.2341 M × 0.010 L = 0.002341 moles
Step:3. Determine the stoichiometric ratio between H2SO4 and NaOH: 1:2 (1 mole of H2SO4 reacts with 2 moles of NaOH)
Step:4. Calculate the moles of NaOH required: 0.002341 moles H2SO4 × (2 moles NaOH / 1 mole H2SO4) = 0.004682 moles NaOH
Step:5. Determine the molarity of the NaOH solution: Molarity = moles / Volume = 0.004682 moles / 0.0301 L = 0.1554 M. So, the molarity of the NaOH solution is 0.1554 M.
Learn more about molarity here, https://brainly.com/question/14469428
#SPJ11
Calculate the volume of a solution prepared by diluting a 2.0 L solution of 0.80 M Ca(CO3)2 to 0.30 M. Select the correct answer below: 5.3 L 6.1 L 6.7 L 7.2 L FEEDBACK MORE INSTRUCTION SUBMIT
The U.S. Geological Survey's procedures for organising and carrying out investigations on water resources are described in a series of chapters on methodologies.5.3 Temperature affects the standard heat of reaction.
2*0.8= 0.3 V
V= 1.6/0.3
= 5.3. Users of the Code may obtain the wording of the provisions in effect by searching for an OMB control number displayed by federal agencies.The manual balances the need for comprehensive coverage by giving an overview of the application of nuclear techniques in soil science and plant nutrition.
To know more about water resources, click here:
https://brainly.com/question/27327901
#SPJ4
what is the purpose of transforming aniline (2) into acetanilide (3) before performing the bromination step
The purpose of transforming aniline into acetanilide before performing the bromination step is to increase the selectivity of the reaction. Aniline is a highly reactive compound and can undergo unwanted side reactions such as self-condensation or oxidation during the bromination process.
These side reactions can lead to a decrease in the yield of the desired product and the formation of unwanted byproducts. Acetanilide, on the other hand, is a more stable compound that is less likely to undergo these side reactions.
By converting aniline into acetanilide, the bromination reaction becomes more selective, resulting in a higher yield of the desired product, which is 4-bromoacetanilide.
Furthermore, acetanilide has a lower solubility in water compared to aniline, making it easier to isolate the product after the reaction is complete. Overall, the transformation of aniline into acetanilide serves to improve the efficiency of the bromination reaction and increase the purity of the final product.
To know more about aniline refer here:
https://brainly.com/question/13887633#
#SPJ11
how many calcium ions are there in 2.64 mol ca3n2 ?
In 2.64 mol of Ca3N2, there are 7.92 mol of calcium ions (Ca2+). This is because there are 3 moles of Ca2+ for every mole of Ca3N2. To find the number of calcium ions, you can use Avogadro's number (6.022 x 10^23 ions/mol): (2.64 mol Ca3N2) x (3 mol Ca2+ / 1 mol Ca3N2) = 7.92 mol Ca2+ (7.92 mol Ca2+) x (6.022 x 10^23 ions/mol) ≈ 4.77 x 10^24 calcium ions.
To find the number of calcium ions in 2.64 mol of Ca3N2, we first need to calculate the number of moles of calcium ions in Ca3N2.
Ca3N2 is composed of three calcium ions (Ca2+) and two nitride ions (N3-). This means that for every molecule of Ca3N2, there are three calcium ions.
So, to find the number of moles of calcium ions in 2.64 mol of Ca3N2, we can use the following formula:
moles of Ca2+ = (moles of Ca3N2) x (3 Ca2+ ions / 1 Ca3N2 molecule)
moles of Ca2+ = 2.64 mol x (3 Ca2+ ions / 1 Ca3N2 molecule)
moles of Ca2+ = 7.92 mol
Therefore, there are 7.92 mol of calcium ions in 2.64 mol of Ca3N2.
To find the actual number of calcium ions, we can use Avogadro's number:
number of Ca2+ ions = (moles of Ca2+) x (Avogadro's number)
number of Ca2+ ions = 7.92 mol x (6.022 x 10^23 ions/mol)
number of Ca2+ ions = 4.77 x 10^24 ions
So, there are approximately 4.77 x 10^24 calcium ions in 2.64 mol of Ca3N2.
Learn more about calcium ions here:
https://brainly.com/question/28504818
#SPJ11
Whenever a gas expands isothermally, such as when you exhale or when a flask is opened, the gas undergoes an increase in entropy. A sample of methane gas of mass 15 g at 260 K and 105 kPa expands isothermally and (a) revers- ibly, (b) irreversibly until its pressure is 1.50 kPa. Calculate the change in entropy of the gas.
When a gas expands isothermally, its temperature remains constant throughout the process. Therefore, the change in entropy can be calculated using the equation:
ΔS = nRln(V₂/V₁)
where ΔS is the change in entropy, n is the number of moles of gas, R is the gas constant, V₁ is the initial volume, and V₂ is the final volume.
(a) Reversibly expanding the methane gas at 260 K and 105 kPa until its pressure is 1.50 kPa, we can use the ideal gas law to calculate the initial volume:
PV = nRT
V₁ = (nRT)/P₁ = (15 g)/(16.043 g/mol) x (0.08206 L·atm/(mol·K)) x 260 K/105 kPa = 0.286 L
Similarly, we can calculate the final volume:
V₂ = (nRT)/P₂ = (15 g)/(16.043 g/mol) x (0.08206 L·atm/(mol·K)) x 260 K/1.50 kPa = 5.00 L
Substituting these values into the entropy equation, we get:
ΔS = (15 g)/(16.043 g/mol) x (0.08206 L·atm/(mol·K)) x ln(5.00 L/0.286 L) = 25.1 J/K
Therefore, the change in entropy of the methane gas when it isothermally and reversibly expands from 105 kPa to 1.50 kPa is 25.1 J/K.
(b) Irreversibly expanding the methane gas until its pressure is 1.50 kPa, we cannot use the same equation as in part (a) because the process is not reversible. Instead, we need to use the equation:
ΔS = q/T
where q is the heat transferred and T is the temperature.
Since the expansion is irreversible, the heat transferred is not equal to the work done on or by the gas. However, we can use the fact that the internal energy of an ideal gas depends only on its temperature to write:
ΔU = 0 = q - w
where ΔU is the change in internal energy and w is the work done on or by the gas. Since the expansion is isothermally and the temperature remains constant, we can write:
w = nRTln(V₂/V₁) = -q
Therefore, the heat transferred can be calculated as:
q = -nRTln(V₂/V₁)
Substituting this into the entropy equation, we get:
ΔS = -(15 g)/(16.043 g/mol) x (0.08206 L·atm/(mol·K)) x ln(5.00 L/0.286 L) / 260 K = 22.1 J/K
Therefore, the change in entropy of the methane gas when it isothermally and irreversibly expands from 105 kPa to 1.50 kPa is 22.1 J/K.
Learn more about internal energy here:
https://brainly.com/question/11742607
#SPJ11
How many kilograms of sodium chloride will be needed to produce 17kg of chlorine?
To make 17 kg of chlorine, around 7.0031 kg of sodium chloride will be required.
Sodium chloride (NaCl) is generally electrolyzed to produce chlorine in a procedure known as chloralkali electrolysis.
The Chemical Equation for this reaction is:
2 NaCl + 2 H₂O → 2 NaOH + Cl₂ + H₂
According to this equation, 1 mole of Cl₂ is created for every 2 moles of NaCl.
NaCl has a molar mass of roughly 58.44 g/mol, while Cl₂ has a molar mass of roughly 70.90 g/mol.
We must first determine the number of moles of Cl₂ created in order to determine the quantity of NaCl necessary to make 17 kg of Cl₂:
Number of moles of Cl₂ = (17 kg) / (70.90 g/mol) = 240.03 mol
We just require half as many moles of NaCl since 1 mole of Cl₂ is created from 2 moles of NaCl:
Number of moles of NaCl = 1/2 × 240.03 mol = 120.015 mol
Finally, we can determine the necessary mass of NaCl:
Mass of NaCl = (120.015 mol) × (58.44 g/mol) = 7,003.1 g = 7.0031 kg
In order to make 17 kg of chlorine, roughly 7.0031 kg of sodium chloride will be required.
To learn more about Stoichiometry:
https://brainly.com/question/14935523
What concentration of aqueous NH3 is necessary to just start precipitation of Mn(OH)2 from a 0.020 M solution MnSO4? Kb for NH3 is 1.8 × 10−5 and Ksp for Mn(OH)2 is 4.6 × 10−14.
a. 1.4 × 10^−5 M
b. 3.7 × 10^−7 M
c. 1.6 × 10^−6 M
d. 1.3 × 10^−7 M
e. 8.4 × 10^−2 M
The concentration of aqueous NH3 required to just start precipitation of Mn(OH)2 from a 0.020 M solution of MnSO4 is 8.4 × 10^−2 M
To determine the concentration of aqueous NH3 necessary to just start precipitation of Mn(OH)2 from a 0.020 M solution of MnSO4, we need to use the given Kb for NH3 and the Ksp for Mn(OH)2.
First, find the concentration of OH- ions needed to start the precipitation using the Ksp expression for Mn(OH)2:
Ksp = [Mn2+][OH-]^2
4.6 × 10^−14 = (0.020)[OH-]^2
Solve for [OH-]:
[OH-] = √(4.6 × 10^−14 / 0.020) ≈ 4.8 × 10^−7 M
Now, use the Kb expression for NH3 to find the required concentration of NH3:
Kb = [NH4+][OH-] / [NH3]
1.8 × 10^−5 = [NH4+][4.8 × 10^−7] / [NH3]
Assume that [NH4+] and [OH-] are equal since they come from the same source (NH3). Therefore:
1.8 × 10^−5 = [4.8 × 10^−7]^2 / [NH3]
Solve for [NH3]:
[NH3] ≈ 8.4 × 10^−2 M
Your answer: e. 8.4 × 10^−2 M
Know more about Ksp here:
https://brainly.com/question/27132799
#SPJ11
when a 4.00 g sample of rbbr is dissolved in water in a calorimeter that has a total heat capacity of 1.39 kj⋅k−1, the temperature decreases by 0.380 k. calculate the molar heat of solution of rbbr.
The molar heat of solution of RbBr is 11.3 kJ/mol.
To calculate the molar heat of solution of RbBr, we can use the formula:
ΔHsoln = q / n
where ΔHsoln is the molar heat of solution, q is the heat absorbed or released during the dissolution process, and n is the number of moles of RbBr dissolved.
To find q, we can use the equation:
q = CΔT
where C is the heat capacity of the calorimeter and ΔT is the temperature change.
Substituting the given values into the equation, we have:
q = (1.39 kJ/K) × 0.380 K
q = 0.5282 kJ
Next, we need to calculate the number of moles of RbBr dissolved. The molar mass of RbBr is:
M(RbBr) = 85.47 g/mol
Therefore, the number of moles of RbBr dissolved is:
n = 4.00 g / 85.47 g/mol
n = 0.0468 mol
Now we can calculate the molar heat of solution of RbBr:
ΔHsoln = q / n
ΔHsoln = (0.5282 kJ) / (0.0468 mol)
ΔHsoln = 11.3 kJ/mol
Therefore, the molar heat of solution of RbBr is 11.3 kJ/mol.
Click the below link, to learn more about Molar heat:
https://brainly.com/question/29435378
#SPJ11
The molar heat of solution of RbBr is 11.3 kJ/mol.
To calculate the molar heat of solution of RbBr, we can use the formula:
ΔHsoln = q / n
where ΔHsoln is the molar heat of solution, q is the heat absorbed or released during the dissolution process, and n is the number of moles of RbBr dissolved.
To find q, we can use the equation:
q = CΔT
where C is the heat capacity of the calorimeter and ΔT is the temperature change.
Substituting the given values into the equation, we have:
q = (1.39 kJ/K) × 0.380 K
q = 0.5282 kJ
Next, we need to calculate the number of moles of RbBr dissolved. The molar mass of RbBr is:
M(RbBr) = 85.47 g/mol
Therefore, the number of moles of RbBr dissolved is:
n = 4.00 g / 85.47 g/mol
n = 0.0468 mol
Now we can calculate the molar heat of solution of RbBr:
ΔHsoln = q / n
ΔHsoln = (0.5282 kJ) / (0.0468 mol)
ΔHsoln = 11.3 kJ/mol
Therefore, the molar heat of solution of RbBr is 11.3 kJ/mol.
Click the below link, to learn more about Molar heat:
https://brainly.com/question/29435378
#SPJ11
What is the ph of the resulting solution if 25.00 ml of 0.10 m acetic acid is added to 10.00 ml of 0.10 m NaOH? assume that the volumes of the solutions are additive. ka = 1.8 × 10^-5 for CH3CO2h.
The pH of the resulting solution if 25.00 ml of 0.10 m acetic acid is added to 10.00 ml of 0.10 m NaOH is 5.80.
To solve this problem, we need to use the equation for the acid-base reaction between acetic acid and sodium hydroxide:
CH₃CO₂H + NaOH → CH₃CO₂Na + H₂O
First, we need to calculate the number of moles of acetic acid and sodium hydroxide:
n(acetic acid) = V(acetic acid) x C(acetic acid) = 25.00 mL x 0.10 mol/L = 0.00250 mol
n(sodium hydroxide) = V(sodium hydroxide) x C(sodium hydroxide) = 10.00 mL x 0.10 mol/L = 0.00100 mol
Next, we need to determine the limiting reagent. Since the stoichiometric ratio of acetic acid to sodium hydroxide is 1:1, we can see that sodium hydroxide is the limiting reagent because there are fewer moles of it.
The reaction between sodium hydroxide and acetic acid will produce sodium acetate and water. We can calculate the number of moles of sodium acetate produced using the balanced equation:
n(sodium acetate) = n(sodium hydroxide) = 0.00100 mol
Now, we need to calculate the concentration of acetic acid and acetate ion in the final solution. Since the volumes are additive, the total volume of the solution is:
V(total) = V(acetic acid) + V(sodium hydroxide) = 25.00 mL + 10.00 mL = 35.00 mL = 0.035 L
The concentration of acetate ion is equal to the moles of acetate ion divided by the total volume of the solution:
C(acetate ion) = n(sodium acetate) / V(total) = 0.00100 mol / 0.035 L = 0.0286 mol/L
Finally, we can calculate the pH of the resulting solution using the Ka expression for acetic acid:
Ka = [H⁺][CH₃CO₂⁻]/[CH₃CO₂H]
[H⁺] = Ka x [CH₃CO₂H] / [CH₃CO₂⁻]
[H⁺] = [tex](1.8 * 10^{-5})[/tex] x (0.00250 mol/L) / (0.0286 mol/L)
[H⁺] = [tex]1.57 * 10^{-6} M[/tex]
pH = -log[H⁺]
pH = [tex]-log(1.57 * 10^{-6})[/tex]
pH = 5.80
Therefore, the pH of the resulting solution is 5.80.
To know more about pH, refer to the link below:
https://brainly.com/question/16639754#
#SPJ11
A mixture of CO(g) and O2(g) in a 1.1 −L container at 1.0×103 K has a total pressure of 2.3 atm . After some time the total pressure falls to 1.8 atm as the result of the formation of CO2.
Find the mass (in grams) of CO2 that forms.
The mass of [tex]CO_{2}[/tex] that forms is approximately 0.299 grams.
How to calculate the mass of a gas ?The term "partial pressure" refers to the pressure that one gas in a combination imposes. Partial pressure refers to the pressure exerted by a gas in a gas mixture if it alone inhabited the entire volume occupied by the combination.
To find the mass of [tex]CO_{2}[/tex] that forms in the reaction between CO(g) and [tex]O_{2}[/tex](g) in a 1.1-L container at 1.0x10^3 K with an initial total pressure of 2.3 atm and a final total pressure of 1.8 atm, follow these steps:
1. Calculate the initial moles of the gas mixture:
Use the ideal gas law, PV = nRT. Rearrange to solve for n: n = PV / RT.
Initial moles (n_initial) = (2.3 atm)(1.1 L) / (0.0821 L atm/mol K)(1.0x10^3 K)
= 0.0309 moles.
2. Calculate the final moles of the gas mixture:
Final moles (n_final) = (1.8 atm)(1.1 L) / (0.0821 L atm/mol K)(1.0x10^3 K)
= 0.0241 moles.
3. Determine the moles of [tex]CO_{2}[/tex] formed:
Moles of [tex]CO_{2}[/tex] (n_ [tex]CO_{2}[/tex])
= n_initial - n_final = 0.0309 moles - 0.0241 moles
= 0.0068 moles.
4. Calculate the mass of [tex]CO_{2}[/tex] formed:
Mass of [tex]CO_{2}[/tex] (m_ [tex]CO_{2}[/tex])
= n_ [tex]CO_{2}[/tex] x molar mass of [tex]CO_{2}[/tex]
= 0.0068 moles x 44.01 g/mol = 0.299 grams.
To know more about Partial Pressures:
https://brainly.com/question/13199169
#SPJ11
determine whether each salt is generally classified as soluble or insoluble in water.
MgCO₃ =
Ba(NO₃)₂ =
Ca₃(PO₄)₂ =
AgBr =
Ag₂SO₄ =
Na₂SO₄ =
NaNO₃ =
Al₂(SO₄)₃ =
Soluble salts in water: Ba(NO₃)₂, Na₂SO₄, NaNO₃, Al₂(SO₄)₃ and insoluble salts are: MgCO₃, Ca₃(PO₄)₂, AgBr, Ag₂SO₄.
To determine whether each salt is generally classified as soluble or insoluble in water, consider the following guidelines:
1. Most nitrate (NO₃⁻) and alkali metal (Group 1) salts are soluble.
2. Most sulfate (SO₄²⁻) salts are soluble, with some exceptions.
3. Most carbonate (CO₃²⁻), phosphate (PO₄³⁻), and hydroxide (OH⁻) salts are insoluble, with some exceptions.
4. Most chloride (Cl⁻), bromide (Br⁻), and iodide (I⁻) salts are soluble, with some exceptions.
Based on these guidelines:
MgCO₃ = Insoluble (carbonate)
Ba(NO₃)₂ = Soluble (nitrate)
Ca₃(PO₄)₂ = Insoluble (phosphate)
AgBr = Insoluble (exception to halides)
Ag₂SO₄ = Insoluble (exception to sulfates)
Na₂SO₄ = Soluble (sulfate)
NaNO₃ = Soluble (nitrate)
Al₂(SO₄)₃ = Soluble (sulfate)
Know more about Salts here:
https://brainly.com/question/14467184
#SPJ11
When the pressure is increased on the following system at equilibrium, 3H2(g) + N2(g) =2 NH3(g), by decreasing the volume to half of the initial volume, A. In order to restore equilibrium, the reaction shifts right, toward products B. In order to restore equilibrium, the reaction shifts left toward reactants C. No change occurs D. None of the above
There are 4 moles of gas on the left side (3H2 + N2) and 2 moles on the right side (2NH3), the reaction will shift right, toward products, to restore equilibrium. Therefore, the correct answer is A. In order to restore equilibrium, the reaction shifts right, toward products.
When the pressure is increased on the given system at equilibrium, decreasing the volume to half of the initial volume, the reaction will shift in the direction that produces fewer moles of gas. In this case, the reaction produces 2 moles of NH3 from 4 moles of gas (3 moles of H2 and 1 mole of N2). Therefore, the reaction will shift right towards products to reduce the pressure.
So, the correct answer is A. In order to restore equilibrium, the reaction shifts right, toward products.
When the pressure is increased on the following system at equilibrium, 3H2(g) + N2(g) = 2NH3(g), by decreasing the volume to half of the initial volume, the reaction shifts to restore equilibrium. According to Le Chatelier's principle, the system will shift to counteract the change in pressure. In this case, it will shift towards the side with fewer moles of gas to reduce pressure.
Since there are 4 moles of gas on the left side (3H2 + N2) and 2 moles on the right side (2NH3), the reaction will shift right, toward products, to restore equilibrium. Therefore, the correct answer is A. In order to restore equilibrium, the reaction shifts right, toward products.
To learn more about Moles, click here:
brainly.com/question/26416088
#SPJ11
Sort the following compounds into the appropriate bins based on the type of stereoisomerism they exhibit (or lack of thereof). Note that all halogens and hydrogens are terminal atoms, each connected to a carbon atom. o Neither Geometric nor Optical o Geometric o Optical • CCl2=CHI • CHCI=CHCH2C1 • CH3-CH2-CH=CH-CH2-CH3 • CH2CH(CBrz)CH2CH3 • CH3CHCICH Br
Neither Geometric nor Optical:
- CH3CHCICHBr
Geometric:
- CCl2=CHI
- CHCl=CHCH2Cl
- CH2CH(CBr2)CH2CH3
Optical:
- CH3-CH2-CH=CH-CH2-CH3
In organic chemistry, stereoisomers are compounds that have the same molecular formula and the same connectivity of atoms, but differ in the way that the atoms are arranged in space.
Geometric isomers are a type of stereoisomerism that occurs in compounds that have restricted rotation around a double bond or a ring. Geometric isomers have different spatial arrangements of groups on either side of the double bond or within the ring. The compounds CCl2=CHI, CHCl=CHCH2Cl, and CH2CH(CBr2)CH2CH3 all have double bonds and therefore exhibit geometric isomerism.
Optical isomers are a type of stereoisomerism that occurs in compounds that have an asymmetric carbon atom, which is a carbon atom that is bonded to four different groups. Optical isomers are mirror images of each other and cannot be superimposed on one another. The compound CH3-CH2-CH=CH-CH2-CH3 has an asymmetric carbon atom and therefore exhibits optical isomerism.
The compound CH3CHCICHBr does not have any double bonds or asymmetric carbon atoms, so it does not exhibit either geometric or optical isomerism and is classified as neither.
Visit to know more about Optical:-
brainly.com/question/30438544
#SPJ11
The hydroxide ion concentration of an aqueous solution of 0.355 M hydrocyanic acid is [OH-] = _______ M. The pH of an aqueous solution of 0.595 M acetic acid is______
The hydroxide ion concentration of an aqueous solution of 0.355 M hydrocyanic acid is 7.27 x 10⁻⁶ M.
How we can hydrocyanic aqueous solution of acetic acid?To find the hydroxide ion concentration of an aqueous solution of 0.355 M hydrocyanic acid, we need to first write the balanced chemical equation for the dissociation of hydrocyanic acid in water:
[tex]HCN + H2O[/tex]⇌ [tex]H3O+ + CN-[/tex]
The acid dissociation constant, Ka, for hydrocyanic acid is 4.9 x 10⁻¹°. We can write the expression for the acid dissociation constant:
Ka =[tex][H3O+][CN-] / [HCN][/tex]
Since we are looking for the hydroxide ion concentration, [OH-], we can use the relationship between the concentration of hydroxide ions and the concentration of hydronium ions:
Kw = [tex][H3O+][OH-][/tex]
At 25°C, the value of the ion product constant, Kw, is 1.0 x 10⁻¹⁴. Using the expression for Kw, we can find the concentration of hydroxide ions:
[tex][OH-][/tex] = [tex]Kw / [H3O+][/tex]
[tex][OH-][/tex]= [tex]1.0 x 10⁻¹⁴ / [H3O+][/tex]
To find [H3O+], we can use the expression for the acid dissociation constant and the concentration of hydrocyanic acid:
Ka = [tex][H3O+][CN-] / [HCN][/tex]
[tex][H3O+][/tex] = [tex]Ka x [HCN] / [CN-][/tex]
Substituting this into the expression for [OH-], we get:
[tex][OH-][/tex] = 1.0 x 10⁻¹⁴ / [tex](Ka x [HCN] / [CN-])[/tex]
[tex][OH-][/tex] = [tex]([CN-] / Ka) x (1 / [HCN])[/tex] x 1.0 x 10⁻¹⁴
[tex][OH-][/tex]= (0.355 M / 4.9 x 10⁻¹°) x (1 / 0.355 M) x 1.0 x 10⁻¹⁴
[tex][OH-][/tex]= 7.27 x 10⁻⁶ M
To find the pH of an aqueous solution of 0.595 M acetic acid, we need to first write the balanced chemical equation for the dissociation of acetic acid in water:
[tex]CH3COOH + H2O ⇌ H3O+ + CH3COO-[/tex]
The acid dissociation constant, Ka, for acetic acid is 1.8 x 10⁻⁵. We can write the expression for the acid dissociation constant:
Ka = [tex][H3O+][CH3COO-] / [CH3COOH][/tex]
To find the pH, we can use the relationship between the concentration of hydronium ions and the pH:
pH = -log[tex][H3O+][/tex]
To find [H3O+], we can use the expression for the acid dissociation constant and the concentration of acetic acid:
Ka = [tex][H3O+][CH3COO-] / [CH3COOH][/tex]
[tex][H3O+][/tex] = Ka x [tex][CH3COOH] / [CH3COO-][/tex]
Substituting this into the expression for pH, we get:
pH = -log[tex](Ka x [CH3COOH] / [CH3COO-])[/tex]
pH = -log(Ka) - log[tex]([CH3COOH] / [CH3COO-])[/tex]
pH = -log(1.8 x 10⁻⁵) - log(0.595 [tex]M / [CH[/tex]
Learn more about hydrocyanic
brainly.com/question/28590511
#SPJ11
between a water molecule and a cation, like na , a _____a_____ occurs between a _____b_____ of the water molecule and the cation.
Between a water molecule and a cation, like Na+, an electrostatic attraction occurs between a partial negative charge (oxygen) of the water molecule and the cation.
Here's a step-by-step explanation:
1. A water molecule is a polar molecule, which means it has areas with partial positive and partial negative charges. The oxygen atom has a partial negative charge, and the two hydrogen atoms have partial positive charges.
2. A cation, like Na+, is a positively charged ion.
3. When a cation is near a water molecule, the partial negative charge (oxygen) of the water molecule is attracted to the positively charged cation, creating an electrostatic attraction between them. This interaction is also called ion-dipole interaction.
So, an electrostatic attraction occurs between a partial negative charge (oxygen) of the water molecule and the cation (like Na+).
Learn more about cations at https://brainly.com/question/30754382
#SPJ11
a sample of an unknown substances has a heat capacity of 4.29 j/g °c and a mass of 9.9 kg. how much heat (in kcal) must be added to warm the solution from 7.9 °cto 94.5°c?
The amount of heat required to warm the substance from 7.9 °c to 94.5 °c is 907.3 kcal.
To solve this problem, we need to use the following formula:
Q = m × C × ΔT
where Q is the amount of heat, m is the mass of the substance, C is the specific heat capacity, and ΔT is the change in temperature.
We are given that the heat capacity (C) of the substance is 4.29 j/g °c and its mass (m) is 9.9 kg. We need to find the amount of heat (Q) required to raise the temperature from 7.9 °c to 94.5 °c.
First, we need to convert the units of the specific heat capacity from j/g °c to kcal/kg °c. We can do this by dividing 4.29 by 4.184 (the conversion factor between joules and calories) and multiplying by 1,000 (the conversion factor between calories and kilocalories):
C = 4.29 / 4.184 × 1,000 = 1.024 kcal/kg °c
Next, we can plug in the values into the formula:
Q = 9.9 kg × 1.024 kcal/kg °c × (94.5 °c - 7.9 °c)
Q = 9.9 kg × 1.024 kcal/kg °c × 86.6 °c
Q = 907.3 kcal
Therefore, the amount of heat required to warm the substance from 7.9 °c to 94.5 °c is 907.3 kcal.
Visit here to learn more about heat capacity : https://brainly.com/question/28302909
#SPJ11
: A 25 ml solution of HBr is completely neutralized by 18 mL of 1.0 M LiOH. What is the concentration of the HBr solution? Would you consider the acid solution to be concentrated or dilute? Justify your answer. Make sure to write the balanced chemical equation to show the neutralization reaction that occurs and use significant figures when solving for the concentration (Equation: MAVA= MBVB).
The HBr solution with a concentration of 0.72 M would be considered concentrated.
The balanced chemical equation for the neutralization reaction between HBr and LiOH is:
HBr + LiOH → LiBr + H2O
According to the equation, 1 mole of HBr reacts with 1 mole of LiOH to produce 1 mole of water.
Using the given volume and concentration of LiOH, we can calculate the number of moles of LiOH used:
moles of LiOH = M x V = 1.0 M x 0.018 L = 0.018 moles
Since the reaction is 1:1 between HBr and LiOH, the number of moles of HBr present in the 25 mL solution is also 0.018 moles.
Using the equation MAVA= MBVB, we can solve for the concentration of the HBr solution:
MA = (MB x VB) / VA = (1.0 M x 0.018 L) / 0.025 L = 0.72 M
Therefore, the concentration of the HBr solution is 0.72 M.
To determine if the solution is concentrated or dilute, we need to compare its concentration to the typical range of concentrations for acid solutions.
Acid solutions with concentrations less than 0.1 M are considered dilute, while those with concentrations greater than 1.0 M are considered concentrated.
learn more about moles here:
https://brainly.com/question/28239680
#SPJ11
The HBr solution with a concentration of 0.72 M would be considered concentrated.
The balanced chemical equation for the neutralization reaction between HBr and LiOH is:
HBr + LiOH → LiBr + H2O
According to the equation, 1 mole of HBr reacts with 1 mole of LiOH to produce 1 mole of water.
Using the given volume and concentration of LiOH, we can calculate the number of moles of LiOH used:
moles of LiOH = M x V = 1.0 M x 0.018 L = 0.018 moles
Since the reaction is 1:1 between HBr and LiOH, the number of moles of HBr present in the 25 mL solution is also 0.018 moles.
Using the equation MAVA= MBVB, we can solve for the concentration of the HBr solution:
MA = (MB x VB) / VA = (1.0 M x 0.018 L) / 0.025 L = 0.72 M
Therefore, the concentration of the HBr solution is 0.72 M.
To determine if the solution is concentrated or dilute, we need to compare its concentration to the typical range of concentrations for acid solutions.
Acid solutions with concentrations less than 0.1 M are considered dilute, while those with concentrations greater than 1.0 M are considered concentrated.
learn more about moles here:
https://brainly.com/question/28239680
#SPJ11
explain why hc--ch is more acidic than ch3ch3, even though the c-h bond in hc-ch has a higher bond dissociation energy than the ch bond in ch3ch3
The reason why HC≡CH (acetylene) is more acidic than CH3CH3 (ethane) is due to the difference in hybridization of the carbon atoms and the resulting stability of the conjugate bases formed upon deprotonation. In HC≡CH, the carbon atom is sp-hybridized, while in CH3CH3, the carbon atom is sp3-hybridized.
When a proton is removed from HC≡CH, the resulting conjugate base is a negatively charged acetylide ion (C≡C-), in which the negative charge is delocalized over the two sp-hybridized carbon atoms. This delocalization of the negative charge leads to a more stable conjugate base, making it easier for the molecule to lose a proton and act as an acid.
On the other hand, when a proton is removed from CH3CH3, the resulting conjugate base is a negatively charged ethyl anion (CH3CH2-), with the negative charge localized on a single sp3-hybridized carbon atom. This conjugate base is less stable than the acetylide ion due to the lack of delocalization, making it harder for ethane to lose a proton and act as an acid.
Thus, even though the C-H bond in HC≡CH has a higher bond dissociation energy than the C-H bond in CH3CH3, HC≡CH is more acidic because its conjugate base is more stable due to the delocalization of the negative charge over the sp-hybridized carbon atoms.
To know more about conjugate bases click here:
https://brainly.com/question/12883745
#SPJ11
What general conclusions can you draw concerning the acidity or basicity of the hydroxides of the elements of the third period? Discuss general trends in metallic and non-metallic properties as shown by your experiment.
Third period hydroxides shows a general trend of increasing acidity and decreasing basicity from left to right, which is related to the metallic and non-metallic properties of the elements.
Based on the acidity and basicity of the hydroxides of elements in the third period, we can draw some general conclusions. Typically, as we move from left to right across the period, the acidity of hydroxides increases while the basicity decreases. This trend is related to the metallic and non-metallic properties of the elements.
Towards the left side of the period, elements exhibit more metallic properties, which results in their hydroxides being more basic. Examples include sodium (Na) and magnesium (Mg). As we progress towards the right side of the period, elements become more non-metallic, and their hydroxides display more acidic properties. Examples include phosphorus (P) and sulfur (S).
In summary, the acidity and basicity of hydroxides in the third period are influenced by the metallic and non-metallic properties of the elements. The trend shows that hydroxides become more acidic and less basic as we move from left to right across the period.
Know more about Hydroxide here:
https://brainly.com/question/21904397
#SPJ11
How many atoms are contained in 6 grams of carbon monoxide CO?
Answer: There are nine atoms in carbon monoxide (CO). One atom of carbon (C) and one atom of oxygen (O).
Explanation:
a two-word phrase in each box. the value of the ___ q is equal to the ___ k, when equilibrium is reacted
The value of the "reaction quotient (Q)" is equal to the "equilibrium constant (K) when equilibrium is reached.
The reaction quotient (Q) is a measure of the relative concentrations of reactants and products in a chemical reaction at a given point in time, before the reaction has reached equilibrium. It is calculated in the same way as the equilibrium constant (K_eq), but using the current concentrations of the reactants and products rather than their equilibrium concentrations.
The equilibrium constant, denoted by K, is a quantitative measure of the extent to which a chemical reaction proceeds to reach equilibrium. It relates the concentrations of the products and reactants at equilibrium, under a given set of conditions.
Learn more about equilibrium:
https://brainly.com/question/2162534
#SPJ11