Joseph Priestly is frequently credited with the discovery of oxygen, and was reported to have produced molecular oxygen from the decomposition reaction of mercury(II) oxide, which is the reverse of the synthesis of HgO depicted in the following equation. 4 Hg(l) + 2 O2(g) LaTeX: \rightarrow → 4 HgO(s) Determine the value of LaTeX: \Delta ΔH°rxn for the synthesis, given that
Joseph Priestly is frequently credited with the discovery of oxygen, and was reported to have produced molecular oxygen from the decomposition reaction of mercury(II) oxide, which is the reverse of the synthesis of HgO depicted in the following equation. [tex]4Hg(l)+2O_2(g)\rightarrow 4 HgO(s) [/tex]Determine the value of [tex]\Delta ΔH°rxn[/tex] for the synthesis, given that [tex]\Delta H_f^0[/tex] for HgO is -90.7 kJ/mol.
Answer: The enthalpy change for this reaction is, -362.8 kJ
Explanation:
The balanced chemical reaction is,
[tex]4Hg(l)+2O_2(g)\rightarrow 4HgO(s)[/tex]
The expression for enthalpy change is,
[tex]\Delta H=\sum [n\times \Delta H_f(product)]-\sum [n\times \Delta H_f(reactant)][/tex]
[tex]\Delta H=[(n_{HgO}\times \Delta H_{HgO})]-[(n_{O_2}\times \Delta H_{O_2})+(n_{Hg}\times \Delta H_{Hg})][/tex]
where,
n = number of moles
[tex]\Delta H_{O_2}=0[/tex] (as heat of formation of substances in their standard state is zero
[tex]\Delta H_{Hg}=0[/tex] (as heat of formation of substances in their standard state is zero
Now put all the given values in this expression, we get
[tex]\Delta H=[(4\times -90.7)]-[(2\times 0)+(4\times 0)][/tex]
[tex]\Delta H=-362.8kJ[/tex]
Therefore, the enthalpy change for this reaction is, -362.8 kJ
3.
What do we call materials
that let heat pass through
them easily?
Thermal conductors
Thermal insulators
Transparent
4.
Which of these is a good
thermal conductor?
Plastic
Wood
Steel
5.
Which of these is a good
thermal insulator?
Steel
Iron
Polystyrene
6.
To save on heating bills, do
you think the roof of a
building should be lined with...
a thermal conductor
a thermal insulator
nothing
7.
How does heat travel?
From cold things to hotter things
From hot things to colder things
Between things of the same temperature
Answer:
thermal conductors
steel
polystyrene
thermal insulator
between things of the same temp?
sorry to ask but if its ok with you, may i get brainly, i need to rank up all i need is two more, if not its fine. thank you and yours truly golden
which statements best describe measuring with a graduated cylinder?
A particle that travels around the nucleus of an atom in orbitals is called a(n)
Answer: electrons
Explanation:
Answer: It is called an electron because it is attracted to the positively charged particales called protons in the center of the atom.
Explanation:
Draw the structure(s) of the major organic product(s) of the following reaction. 1. lithium diisopropylamide / hexane 2. 1 eq. CH3I You do not have to consider stereochemistry. Omit products derived from the acidic or basic reagent itself, e.g. HN(i-Pr)2 derived from N(i-Pr)2-. If no reaction occurs, draw the organic starting material. If substantial starting material is present at the end of the reaction, include it in the products. Draw one structure per sketcher. Add additional sketchers using the drop-down menu in the bottom right corner. Separate structures with signs from the drop-down menu.
Answer:
See explanation below
Explanation:
You are not providing the starting material, however, I manage to find a similar question to this, so I'm gonna use it as a basis to help you answer yours.
Now let's analyze what is happening in the reaction so we can predict the final product.
We have a ketone here, reacting at first with LDA. This is a very strong base that is commonly used in reactions with ketones and aldehydes to promove a condensation. To do this, as LDA is a strong base it will occur firts an acid base reaction, substracting the most acidic hydrogen in the molecule (Which in this case, is the Beta hydrogen of the carbonile). This will cause an enolate formation.
Then, this enolate will react with the CH3I and form a new product. The final result would be a ketone with a methyl group now attached. In the picture 2, you have the mechanism and final product.
Hope this helps
how far does light travel in 3.0 days
Answer:
[tex]d=7.77\times 10^{13}\ m[/tex]
Explanation:
We know that the speed of light is equal to [tex]3\times 10^8\ m/s[/tex]
We need to find how far the light travel in 3 days.
Speed of an object is equal to distance covered divided by time taken.
Also, 1 day = 86400 s
3 days = 259200 s
So,
[tex]d=vt[/tex]
[tex]d=3\times 10^8\times 259200\\\\d=7.77\times 10^{13}\ m[/tex]
So, the light will travel [tex]7.77\times 10^{13}\ m[/tex] in 3 days.
Question 4 of 10
What form of the ideal gas law would you use to calculate the temperature of
a gas?
O A. Ta
B. Y =
C. P = nRT
D. n =
RT
Answer:
C. P = nRT
Explanation:
PV = nRT, where n is a number of moles and R is the universal gas constant, R = 8.31 J/mol ⋅ K.
Hope this helps :)
Answer:T =PV/nR
Explanation:
Temperature can weather rocks because A heat can cause minerals to oxidize B. most rocks do not absorb heat evenly C. water contracts when it freezes D. rocks usually melt in the hot sun
Answer:
b
Explanation:
it is not c because water expands when it freezes.
Nitrogen dioxide (NO2) is a toxic gas produced by cars and factories. If a car produces one mole of NO2 during a 10 mile drive, how many grams of nitrogen dioxide are produced?
Answer:
Explanation:
molecular weight of NO₂ is 14 + 2 x 16 = 46
So one mole of nitrogen dioxide will have mass of 46 grams .
Based on the following chemical equation how many molecules of Hydrogen (H) are present in the reactants side?
2H2 + O2 ----> 2H2O
Question 1 options:
1
2
3
4
Answer:
2
Explanation:
Based on the chemical equation, the number of molecules of hydrogen gas in the reactant side is 2.
This is indicated by the coefficient before reactant.
A molecule is a covalent compound that has discrete or separate units.
So H₂ is made up of two atoms of hydrogen that has been covalently bonded together by sharing their valence electrons.
From the reaction expression:
2 molecules of hydrogen gas combines with 1 molecule of oxygen gas to produce 2 molecules of water.
3.4 x 10-25 kg = ? microounces
Answer: 1.2 x 10^-17 microounces
Explanation:
Ounce = 28.5G microounce = 28.5*10^-6g
3.4*10^-25 kg = 3.4*10^-22 g = (3.4/2.85)*10^(-22+5) = 1.2*10-17
An unknown object has a mass of 150 grams and a volume of 5 cm3. What is the density of this
object?
Answer:
1.2 cm
Explanation:
The reason how I got my answer is by dividing 150 by 125 and that gave me 1.2 cm.
If a gold ring weighs 25 grams. How much energy in Joules would it take to get it to reach its melting point if the ring starts out at 75 degrees C? (melting point is 1064 C, Cp for gold is .129 J/g-C.
Answer:
3.2 × 10³ J
Explanation:
Step 1: Given data
Mass of the gold ring (m): 25 gSpecific heat capacity of gold (Cp): 0.129 J/g.°CInitial temperature: 75 °CFinal temperature: 1064 °CStep 2: Calculate the temperature change (ΔT)
ΔT = 1064 °C - 75 °C = 989 °C
Step 3: Calculate the energy required (Q)
We will use the following expression.
Q = Cp × m × ΔT
Q = 0.129 J/g.°C × 25 g × 989 °C
Q = 3.2 × 10³ J
How can the IR spectrum be used to show that there is not starting material left and the products are alcohols
Answer:
hello your question is incomplete attached below is the complete question
answer :
Absence of c = c = C-H of the peak and the presence of -O-H and C-O peak shows that there is presence of Alcohols as products and it also shows that there is no starting material left
Explanation:
To provide that there is no starting material left and products are alcohols using the IR spectrum we will apply hydroboration oxidation
Absence of c = c = C-H of the peak and the presence of -O-H and C-O peak shows that there is presence of Alcohols as products and it also shows that there is no starting material left
attached below is the detailed solution
Consider the following chemical equilibrium:
NH4SH(s) ⇌ H2SgNH3(g) Now write an equation below that shows how to calculate Kp from Kc for this reaction at an absolute temperature T. You can assume T is comfortably above room temperature. If you include any common physical constants in your equation be sure you use their standard symbols, found in the ALEKS Calculator.
Answer:
See explanation below
Explanation:
First, let's write the reaction:
NH₄SH(s) <------> H₂S(g) + NH₃(g)
The reaction is already balanced so we don't need to do anything else.
Second, let's take into account the following. The Kc expression for this reaction, only compounds in gaseous state are the only ones that contribute to the equilibrium. Solid and liquid do not contribute to the Kc expression. This is because solid and liquid have a constant concentration near to 1, so, it won't do any difference.
Knowing this, the Kc expression for this reaction is:
Kc = [H₂S] [NH₃]
Now, to calculate Kp from Kc, there's an expression that helps a lot to do this. The expression is the following:
Kp = Kc (RT)ᵃⁿ (1)
Where:
R: universal constant of gases
T: Temperature in K
ᵃⁿ = difference of the coefficients of the reaction.
This expression comes from the fact that Kp is an expression that instead of working with concentrations, it works with pressure.
If we use the ideal gas equation we have:
PV = nRT
Solving for P:
P = nRT/V and C = n/V so
P = CRT
If we now replace this, in the Kp expression of equilibrium we have:
Kp = pH₂S * pNH₃
Kp = ([H₂S]RT)¹ ([NH₃]RT)¹
Kp = (RT)¹⁺¹ ([H₂S] [NH₃])
Kp = (RT)²Kc
So finally the expression for Kp would be:
Kp = Kc (RT)²Hope this helps
Will liquid with higher density be more or less buoyant?
Answer:
Explanation:
if it has a lower density than the liquid it's in will float
How many grams of Mo2(S04)3 are in 5.35X10 22 molecules of Mo2 (SO4)3?
Answer:
42.658
Explanation:
1) Avogadro's number is: N(A)=6.02*10²³
2) M of (Mo₂(SO₄)₃)=96*2+96*3=480 (gr/mol);
3) if N(A) ~ 1 mol of (Mo₂(SO₄)₃), tnen 5.35*10²² ~
(5.35*10²²)/(6.02*10²³)≈0.0888 mol of (Mo₂(SO₄)₃);
4) m(Mo₂(SO₄)₃)=M(Mo₂(SO₄)₃)*0.0888;
m((Mo₂(SO₄)₃)=480*0.0888=42.658 (gr)
Rank the following elements by electron affinity, from most positive to most negative EA value.
Rank from most positive to most negative. To rank items as equivalent, overlap them.
bromine
sodium
tellurium
helium
phosphorus
Answer:
Explanation:
Bromine >Tellurium > Phosphorus > Helium > Sodium
Electron affinity of Bromine , Tellurium , Phosphorus are positive , of helium is zero and of sodium is negative .
100 POINTS FOR BEST ANSWER! What is the difference between LDOF and SDOF
An SDOF system is one whose motion is governed by a single, second-order differential equation. Only two variables, position and velocity are needed to describe the trajectory of the system. Many structures can be idealized as single degree-of-freedom systems.
The LDAP Data Interchange Format is a standard plain text data interchange format for representing LDAP directory content and update requests. LDIF conveys directory content as a set of records, one record for each object.
At 25.0°C the Henry's Law constant for dinitrogen monoxide (N2O) gas in water is 0.025 M/atm.
Calculate the mass in grams of N2O gas that can be dissolved in 325. mL of water at 25.0°C and a N2O partial pressure of 0.69 atm.
Be sure your answer has the correct number of significant digits.
Answer:
The mass in grams of N₂O gas that can be dissolved is 0.18 g
Explanation:
The solubility of a gas is proportional to the partial pressure of that gas, over a determined solvent. That's what Henry's law states. We see the formula:
S = K . Pp
Where S is solubility and K is Henry's constant. This specific for each gas and each temperature, while Pp means partial pressure.
We replace data:
S = 0.025 M/atm . 0.69atm
S = 0.01725 M
This is the solubility of the gas, so now, we need to know what mass of gas is solubilized. We convert the moles, with the volume of water.
0.01725 mol/L . 0.235 L = 4.05×10⁻³ moles
Now, we determine the mass in grams: 4.05×10⁻³ mol . 28 g / 1mol =
0.1782 g
A catalyst decreases the activation energy of a particular exothermic reaction by 56 kJ/mol, to 35 kJ/mol. Assuming that the mechanism has only one step, and that the products are 78 kJ lower in energy than the reactants, sketch approximate energy-level diagrams for the catalyzed and uncatalyzed reactions. What is the activation energy for the uncatalyzed reverse reaction
Answer:
Activation energy for the uncatalyzed reverse reaction = 103 kJ/mol
Explanation:
Activation energy decreases from = 56 kj/mol to 35 kj/mol
products = 78 KJ lower in energy than reactants
Activation energy for the uncatalyzed reverse reaction = 103 kJ/mol
attached below are the sketches of approximate energy-level for both catalyzed and uncatalyzed reactions
What does not affect the strength of an electromagnet?
Answer:
Unlike a permanent magnet, an electromagnet can be turned on and off using electrical current. Many variables affect the strength of this electromagnet, and there are some variables that do not affect the strength. ... Making the nail longer will not make the magnet stronger, unless you also add more turns to the coil.
electromagnet can be turned on and off using electrical current. Many variables affect the strength of this electromagnet, and there are some variables that do not affect the strength
Which statement about Niels Bohr's atomic model is true?
O Higher orbits have lower energies.
O Each orbit has a specific energy level.
O Electrons can exist in any energy level.
O Orbits close to the nucleus have no energy.
Answer:
O Each orbit has a specific energy level.
Explanation:
Neils Bohr put forward his own model of the atom based on the quantum mechanics originally developed by Planck.
He assumed the Rutherford's model and suggested that the extranuclear part consists of electrons in specific spherical orbits around the nucleus.
The orbits/energy level are the permissible through which the electrons can move through.
His concept is based the concept that the electron can move round the nucleus in certain permissible orbitss
Write a mechanism for the esterification of propanoic acid with 18O-labeled ethanol. Show clearly the fate of the 18O label. (b) Acid-catalyzed hydrolysis of an unlabeled ester with 18O-labeled water (H218O) leads to incorporation of some 18O into both oxygens of the carboxylic acid product. Explain by a mechanism. (Hint: You must use the fact that all steps in the mechanism are reversible.)
Answer:
See explanation and images attached
Explanation:
a) In the mechanism for the acid catalysed esterification of propanoic acid using ethanol, we can see that the first step is the protonation of the acid followed by nucleophillic attack of the alcohol. Loss of water and consequent deprotonation regenerates the acid catalyst. We can see the fate of the 18O labelled ethanol in the mechanism shown.
b) In the second mechanism, an unnamed ester is hydrolysed using an acid catalyst. The attack of the acid and subsequent nucleophillic attack of water labelled with 18O leads to the incorporation of this 18O into the product acid as shown in the mechanism attached to this answer.
How many moles of sodium are present in 17 g of Na?
What is the number of moles in 60g of Na2SO4?
How many moles are there in 93.5g of CO2?
How many moles are there in 25.6g of Sodium Nitrate?
Determine the number of particles in .75 mol of calcium hydroxide
Answer:
1. 0.74mol
2. 0.42mol
3. 2.125mol
4. 0.301mol
5. 4.52 × 10^23 particles
Explanation:
Number of moles (n) in a substance can be found using the formula:
mole (n) = mass/molar mass
Using this formula, the following moles are calculated:
1. Molar of Na = 23g/mol
mole = 17/23
mole = 0.74mol
2. Molar mass of Na2SO4 = 23(2) + 32 + 16(4)
= 46 + 32 + 64
= 142g/mol
Mole = 60/142
mole = 0.42mol
3. Molar mass of CO2 = 12 + 16(2)
= 12 + 32
= 44g/mol
mole = 93.5/44
mole = 2.125mol
4. Molar mass of sodium nitrate (NaNO3) = 23 + 14 + 16(3)
= 23 + 14 + 48
= 85g/mol
mole = 25.6/85
mole = 0.301mol
5. Number of particles in one mole of a substance is 6.022 × 10^23 particles. Hence, in 0.75mol of calcium hydroxide (Ca(OH)2, there will be;
0.75mol × 6.02 × 10^23
= 4.515 × 10^23
= 4.52 × 10^23 particles
Aniline, consists of carbon, hydrogen, and nitrogen. Combustion of this yields CO2, H20, and N2 as products. If the combustion of 12.5 g of aniline yields 7.1 grams of H2O, and 1.48 grams of N2, what is its empirical formula? [HINT: write out a chemical equation, consider law of conservation of mass, and then think about what percent hydrogen is in water]
A. CHN
B. C2H4N8
C. C16H15N2
D. C20H15N31
The empirical formula : C. C₁₆H₁₅N₂
Further explanationGiven
12.5 g of aniline
7.1 grams of H2O
1.48 grams of N2
Required
The empirical formula
Solution
Reaction :
mass H in H₂O :
= 2.1/18 x 7.1 g
= 0.79
mass N = 1.48
mass C :
= 12.5 g-(mass H+mass N)
= 12.5 - (0.79+1.48)
= 10.23
Mol ratio C : H : N =
= 10.23/12 : 0.79/1 : 1.48/14
= 0.853 : 0.79 : 0.106
= 8 : 7.5 : 1
= 16 : 15 : 2
This diagram is attempting to compare the sizes of the four inner planets. What is wrong with this diagram?
Answer:
points
Explanation:
Answer:
Where is the diagram?
Explanation:
..........................
Methyl salicylate is a common active ingredient in liniments such as ben-gay. It is also known as oil of wintergreen. It is made up of carbon, hydrogen, and oxygen atoms. When a sample of methyl salicylate weighing 5.287 g is burned in excess oxygen, 12.24 g of carbon dioxide and 2.505 g of water are formed. What is the simplist formula for oil of wintergreen
Answer: The empirical formula is [tex]C_3H_3O[/tex].
Explanation:
The chemical equation for the combustion of hydrocarbon having carbon, hydrogen and oxygen follows:
[tex]C_xH_yO_z+O_2\rightarrow CO_2+H_2O[/tex]
where, 'x', 'y' and 'z' are the subscripts of Carbon, hydrogen and oxygen respectively.
We are given:
Mass of [tex]CO_2[/tex] = 12.24 g
Mass of [tex]H_2O[/tex] = 2.505 g
Molar mass of carbon dioxide = 44 g/mol
Molar mass of water = 18 g/mol
For calculating the mass of carbon:
In 44g of carbon dioxide, 12 g of carbon is contained.
So, in 12.24 g of carbon dioxide, =[tex]\frac{12}{44}\times 12.24=3.338g[/tex] of carbon will be contained.
For calculating the mass of hydrogen:
In 18g of water, 2 g of hydrogen is contained.
So, in 2.505 g of water, =[tex]\frac{2}{18}\times 2.505=0.278g[/tex] of hydrogen will be contained.
Mass of oxygen in the compound = (5.287) - (3.338+0.278) = 1.671 g
Step 1 : convert given masses into moles.
Moles of C =[tex] \frac{\text{ given mass of C}}{\text{ molar mass of C}}= \frac{3.338g}{12g/mole}=0.278moles[/tex]
Moles of H=[tex]\frac{\text{ given mass of H}}{\text{ molar mass of H}}= \frac{0.278g}{1g/mole}=0.278moles[/tex]
Moles of O=[tex]\frac{\text{ given mass of O}}{\text{ molar mass of O}}= \frac{1.671g}{16g/mole}=0.104moles[/tex]
Step 2 : For the mole ratio, divide each value of moles by the smallest number of moles calculated.
For C =[tex]\frac{0.278}{0.104}=3[/tex]
For H =[tex]\frac{0.278}{0.104}=3[/tex]
For O =[tex]\frac{0.104}{0.104}=1[/tex]
The ratio of C : H : O = 3: 3: 1
Hence the empirical formula is [tex]C_3H_3O[/tex].
2. According to the U.S. government, 4.9 billion barrels of crude oil flowed into the Gulf of Mexico following the explosion that destroyed the Deepwater Horizon drilling rig in April 2010. Express this volume of crude oil in liters and in cubic kilometers
A 2.0% (w/v) solution of sodium hydrogen citrate, Na2C6H6O7, which also contains 2.5% (w/v) of dextrose, C6H12O6, is used as an anticoagulant for blood which is to be used for transfusions. What is the molarity of the sodium hydrogen citrate in the solution
Answer:
0.0847M is molarity of sodium hydrogen citrate in the solution
Explanation:
The 2.0%(w/v) solution of sodium hydrogen citrate contains 2g of the solute in 100mL of solution. To find the molarity of the solution we need to convert the mass of solute to moles using molar mass and the mL of solution to Liters because molarity is the ratio between moles of sodium hydrogen citrate and liters of solution.
Moles Na2C6H6O7:
Molar Mass:
2Na: 2*22.99g/mol: 45.98g/mol
6C: 6*12.01g/mol: 72.01g/mol
6H: 6*1.008g/mol: 6.048g/mol
7O: 7*16g/mol: 112g/mol
45.98g/mol + 72.01g/mol + 6.048g/mol + 112g/mol = 236.038g/mol
Moles of 2g:
2g * (1mol / 236.038g) = 8.473x10⁻³ moles
Liters solution:
100mL * (1L / 1000mL) = 0.100L
Molarity:
8.473x10⁻³ moles / 0.100L =
0.0847M is molarity of sodium hydrogen citrate in the solutionAnswer:
0.085M
Explanation:
Molecular weight of sodium hydrogen citrate=236.09 g
236.09 g of Na2C6H6O7 in 1000ml= 1 M
2%= 2 g in 1 litre (1000ml)
20/236.09=0.0847 M=0.085 M