Answer:
Specific heat capacity, c = 1.99J/g°C. The reaction is endothermic because heat is being absorbed.
Explanation:
Given the following data;
Mass = 250g
Original temperature, T1 = 35°C
New temperature, T2 = 50°C
Quantity of heat = 7454J
To find the specific heat capacity;
Heat capacity is given by the formula;
[tex] Q = mcdt[/tex]
Where;
Q represents the heat capacity or quantity of heat.
m represents the mass of an object. c represents the specific heat capacity of water. dt represents the change in temperature.dt = T2 - T1
dt = 50 - 35
dt = 15°C
Making "c" the subject of formula, we have;
[tex] c = \frac {Q}{mdt} [/tex]
Substituting the values into the equation, we have;
[tex] c = \frac {7454}{250*15} [/tex]
[tex] c = \frac {7454}{3750} [/tex]
Specific heat capacity, c = 1.99J/g°C.
Therefore, the reaction is endothermic because heat is being absorbed (initial temperature is lower than the final temperature).
Which element is classified as a transition metal?
A) lithium (Li)
B) zirconium (Zr)
C) tellurium (Te)
D) xenon (Xe)
Answer:
C) tellurium (Te) is the correct answer.
first answer will get brainliest
Answer:
Incorrect
Explanation:
Mole ratios are derived from the coefficients in front of the number, N2O does not have a 2 in front of it, the real mole ratio would be 4/1
Answer:
Correct
Explanation:
I had the same problem and I put correct, and it was correct.
PLZ HELP ASAP WILL
GIVE BRAINLISTS TO RIGHT ANSWER
2KCIO3 → 2KCI + 302
How many grams of potassium chloride are produced if 52 g of potassium chlorate decompose?
A )32 g KCI
B )19 g KCI
C)44 g KCI
D)1.5 g KCI
Answer:
A) Mass = 32 g of KCl
Explanation:
Given data:
Mass of potassium chloride produced = ?
Mass of potassium chlorate = 52 g
Solution:
Chemical equation:
2KClO₃ → 2KCl + 3O₂
Number of moles of KClO₃:
Number of moles = mass/molar mass
Number of moles = 52 g/ 122.55 g/mol
Number of moles = 0.424 mol
Now we will compare the moles of KClO₃ and KCl
KClO₃ : KCl
2 : 2
0.424 : 0.424
Mass of KCl:
Mass = number of moles × molar mass
Mass = 0.424 mol × 74.55 g/mol
Mass = 32 g
which of the following is the best thermal insulator?
1. Steel
2. Iron
3. Polystyrene
Answer:
3
Explanation:
Answer:
best guess is polystyrene
Explanation:
16. Using the average atomic masses given in the inside front cover of this book, calculate the indicated quantities.
d. the number of moles of cobalt represented by 5.99 x 1021 cobalt atoms e. the mass of 4.23 mol of cobalt
f. the number of cobalt atoms in 4.23 mol of cobalt
g. the number of cobalt atoms in 4.23 g of cobalt
Answer:
d. 9.95 × 10⁻³ mol
e. 249 g
f. 2.55 × 10²⁴ atoms
g. 4.32 × 10²² atoms
Explanation:
d. the number of moles of cobalt represented by 5.99 x 10²¹ cobalt atoms
We will use Avogadro's number: there are 6.02 × 10²³ atoms of cobalt in 1 mole of atoms of cobalt.
5.99 x 10²¹ atoms × 1 mol/6.02 × 10²³ atoms = 9.95 × 10⁻³ mol
e. the mass of 4.23 mol of cobalt
The molar mass of cobalt is 58.93 g/mol.
4.23 mol × 58.93 g/mol = 249 g
f. the number of cobalt atoms in 4.23 mol of cobalt
We will use Avogadro's number: there are 6.02 × 10²³ atoms of cobalt in 1 mole of atoms of cobalt.
4.23 mol × 6.02 × 10²³ atoms/1 mol = 2.55 × 10²⁴ atoms
g. the number of cobalt atoms in 4.23 g of cobalt
First, we will calculate the moles of cobalt using the molar mass of cobalt.
4.23 g × 1 mol/58.93 g = 0.0718 mol
Then, we will calculate the number of cobalt atoms using Avogadro's number.
0.0718 mol × 6.02 × 10²³ atoms/1 mol = 4.32 × 10²² atoms
3. The doctor notices that Janet has long fingernails, and comments that fingernails grow at a rate (or
speed) of 2.50 cm / year. Convert this speed to kilometers / second. Show your work. (6 pts)
Answer:
7.93 × 10⁻¹³ km/s
Explanation:
Step 1: Given data
Rate of growth of the fingernails (r): 2.50 cm/year
Step 2: Convert "r" from cm/year to km/year
We will use the following conversion factors.
1 m = 100 cm1 km = 1000 m[tex]\frac{2.50cm}{year} \times \frac{1m}{100cm} \times \frac{1km}{1000m} = 2.50 \times 10^{-5} km/year[/tex]
Step 3: Convert "r" from km/year to km/s
We will use the following conversion factors.
1 year = 365 day1 day = 24 h1 h = 60 min1 min = 60 s[tex]\frac{2.50 \times 10^{-5} km}{year} \times \frac{1year}{365day} \times \frac{1day}{24h} \times \frac{1h}{60min} \times \frac{1min}{60s} = 7.93 \times 10^{-13} km/s[/tex]
2.50 cm/year is equal to 7.93 × 10⁻¹³ kilometers/second.
A force of 7 N acts on an object. The displacement is, say 8 m, in the direction of the force. Let us take it that the force acts on the object through the displacement. What is the work done in this case?
Answer:
56 J
Explanation:
Step 1: Given data
Force applied on the object (F): 7 NDisplacement of the object (d): 8 mStep 2: Calculate the work (w) done on the object
We can find the work done on the object using the following expression.
w = F × d × cosθ
where
θ is the angle between F and d
Since F and d occur in the same direction, θ = 0° and cosθ = 1. Then,
w = F × d × 1
w = F × d
w = 7 N × 8 m = 56 J
0
Which is not one of Earth's layers?
A А
crust
B)
inner core
mantle
D
ocean
The ocean is not a part of Earth's layers.
Answer:
Ocean
Explanation:
Which of the following is the set of conditions under which a material becomes a supercritical fluid?
A. real gas point
B. critical point
C. extreme point
D. triple point
(multiple choice)
A student performs an experiment to determine the molar mass of magnesium oxide. The student repeats the experiment five times and collects the following data: 40.220gmol, 40.654gmol, 40.314 gmol, 40.165 gmol, and 40.554 gmol. If the accepted value for the molar mass is 40.304 gmol, what is the percent relative error for the average of this data?
Answer:
Percent relative error = 0.191%
Explanation:
Relative error is a measure of accuracy (How closeness is the measure to the accepted value) for a determined data. The formula is:
Percent relative error = |Experimental - Accepted| / Accepted * 100
Where experimental is the average of the data:
(40.220g/mol + 40.654g/mol + 40.314g/mol + 40.165g/mol + 40.554g/mol) / 5 =
40.381g/mol
Replacing using accepted value = 40.304g/mol:
|40.381g/mol - 40.304g/mol| / 40.304g/mol * 100
Percent relative error = 0.191%The concentration of lithium chlorite solution is 12.0% by mass. In a ___g sample of this solution, there are 238.5g of dissolved lithium chlorate.
Answer is A) 1990 but I do not know to go to there please help!
Mass of sample : 1987.5 g≈1990 g
Further explanationGiven
12% mass of Lithium chlorate
Required
Mass of sample
Solution
%mass = (mass of solute/mass of solution) x 100%
mass of solute = mass of Lithium chlorate = 238.5 g
Input the value :
12/100(0.12) = 238.5 g : mass of solution
mass of solution =238.5 : 0.12
mass of solution = 1987.5≈1990 g
Which of the following has the largest atomic radius?
Answer:
b
Explanation:
S2- has the same electron configuration as which neutral element?
Answer:
ANSWER OS HERE
Explanation:
THE O2- has two more extra electrons due to presence of 2 negative charges so a total of 10 electrons and the element that has 10 electrons in the periodic table in its neutral state is Neon (Ne) ( atomic number (10) = no.of protons = no. of electrons) so neutral element with same electron configuration as O2- is Ne. Log in or register to post comments.
The electron configuration of the neutral atom is an useful place to start when trying to determine the electron configuration of an ion.
What is the idea behind this?The neutral atom in your situation is sulfur (S), which is found in group 16 of period 3 of the periodic chart. A neutral sulfur atom has a total of 16 electrons surrounding its nucleus since sulfur has an atomic number of 16. Thus, a neutral sulfur atom will have the following electron configuration. Now, a neutral sulfur atom receives two more electrons to create the sulfide anion, or S2. These two electrons will be added to the 3p-orbitals, which can hold a maximum of two protons, as you can see in the configuration of the neutral atom. between them, a maximum of six electrons. Thus, the sulfide anion's electron configuration will be the electron configuration of neon, the noble gas that appears before sulfur in the periodic table, will be used in the shorthand notation for noble gases for the sulfide anion.
To know more about Electronic configuration, visit-https://brainly.com/question/13497372
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Calculate the molarity (M) if 3.35g of H3PO4 is dissolved in water to give a total volume of 200mL
Answer:
0.171 M
Explanation:
Step 1: Given data
Mass of H₃PO₄ (solute): 3.35 gVolume of solution (V): 200 mLStep 2: Calculate the moles of solute
The molar mass of H₃PO₄ is 97.99 g/mol.
3.35 g × 1 mol/97.99 g = 0.0342 mol
Step 3: Convert "V" to liters
We will use the conversion factor 1 L = 1000 mL.
200 mL × 1 L/1000 mL = 0.200 L
Step 4: Calculate the molarity of the solution
We will use the definition of molarity.
M = moles of solute / liters of solution
M = 0.0342 mol/0.200 L = 0.171 M
us
If the mole fraction of NaCl in an
aqueous solution is 0.0927, what is
the weight/weight % (percent by
mass) of NaCl.
Molar Mass
Naci: 58.44 g/mol
H2O: 18.016 g/mol
Answer:
24.9%
Explanation:
According to this question, mole fraction of NaCl in an aqueous solution is 0.0927. This means that the mole percent of NaCl in the solution is:
0.0927 × 100 = 9.27%
Let's assume that the solution contains water (solvent) + NaCl (solute), hence, the mole fraction of water will be;
100% - 9.27% = 90.73%
THEREFORE, it can be said that, NaCl contains 0.0927moles while H2O contains 9.073moles
N.B: mole = mass/molar mass
Given the Molar Mass
NaCl: 58.44 g/mol
H2O: 18.016 g/mol
For NaCl;
0.0927 = mass/58.44
mass = 0.0927 × 58.44
5.42g
For H2O;
9.073 = mass/18.016
mass = 9.073 × 18.016
= 16.35g
Total mass of solution = 16.35g + 5.42g = 21.77g
Mass percent of NaCl = mass of NaCl/total mass × 100
% mass of NaCl = 5.42g/21.77g × 100
= 0.249 × 100
= 24.9%
Answer:
24.9
Explanation:
A change of state is a(n)
process.
A. irreversible
B. reversible
Answer:
Changes of states are reversible, you can go from a solid to liquid and liquid to solid.Answer:
Reversible
Explanation:
Changes of state are physical changes in matter. Common changes of the state include melting, freezing, sublimation, deposition, condensation, and vaporization.
Select the correct coefficients to balance the reaction given below.
__Al + ___O₂ → ____ Al₂ O₃
Answer:
4Al+3O2→2Al2O3
Explanation:
why do we need nucleic acid in our cells?
Explanation:
Nucleic acids are the most important macromolecules for the continuity of life. They carry the genetic blueprint of a cell and carry instructions for the functioning of the cell.
Choose the catabolic reaction.
A. Breaking down a complex molecule
B. Synthesizing a complex molecule
C. CO2 and H2O combining to form carbonic acid.
Answer:
B. Synthesizing a complex molecule
Explanation:
Hello!
In this case, since catabolic reactions are related to the synthesis of complex biomolecules and metabolic reactions to the breaking down of complex molecules to obtain energy from (say start), we infer that the appropriate answer is:
B. Synthesizing a complex molecule
Because regardless C. also mentions the synthesis of a compound, carbonic acid is not a complex one in comparison to the biomolecules we produce during our cellular cycles.
Best regards!
When Elsa freezes things, is it an example of an exothermic or
endothermic reaction? Explain.
Answer:
endothermic reaction
Explanation:
When Elsa from Frozen freezes things, it is an example of an endothermic chemical reaction.
An endothermic involves a reaction in which heat is absorbed from the surrounding. Hence the surrounding becomes colder at the end of the the change.
So, Elsa draws heat from the environment and this causes the environment to be colder and things that are in contact with her.
Which of the following is the Arrhenius equation?
Answer:
A is the answer the reason why is because I got it right when I was doing my test
In order to produce some SbCl5, a 1.00 mole sample of SbCl3 is first placed in an empty 2.00 liter container maintained at a temperature different from 182oC. At this temperature, Kc, equals 0.117. How many moles of Cl2 must be added to this container to reduce the number of moles of SbCl3 to 0.700 mole at equilibrium
x = = 0.50 M Answer:
In order to produce some SbCl5, a 1.00 mole sample of SbCl3 is first placed in an empty 2.00 liter container maintained at a temperature different from 182oC. At this temperature, Kc, equals 0.117. How many moles of Cl2 must be added to this container to reduce the number of moles of SbCl3 to 0.700 mole at equilibrium
Moles Cl2 that must be added = 0.40 mol
Explanation:
K = ( = 0.117
Equilibrium concentrations:
= (1.00 - 0.70) mol / 2.00 L = 0.15 M <<---why is it 1.00-0.70???
= 0.700 mole / 2.00L = 0.350 M
= x
Kc = ÷ (0.15) = 0.117
Moles Cl2 at equilibrium = 0.050 mol L x 2.00 L = 0.10 mol
Moles Cl2 needed to make 0.300 mol SbCl3 into SbCl5 = 0.30 mol
Moles Cl2 that must be added = 0.40 mol
The number of atoms in 10. grams of calcium is equal to 6.0 x 1023 multiplied by which number?
Answer:
1.51×10²³ atoms.
Explanation:
From the question given above, the following data were obtained:
Mass of Calcium (Ca = 10 g
Number of atom of Calcium (Ca) =?
The number of atoms present in 10 g of Ca be obtained as follow:
From Avogadro's hypothesis, we understood that 1 mole of any substance contains 6.02×10²³ atoms. This implies that 1 mole Ca contains 6.02×10²³ atoms.
1 mole of Ca = 40 g.
Now, if 40 g of Ca contains 6.02×10²³ atoms.
Therefore, 10 g of Ca will contain = (10 × 6.02×10²³) / 40 = 1.51×10²³ atoms.
Thus, 10 g of calcium contains 1.51×10²³ atoms.
Liquid hexane will react with gaseous oxygen to produce gaseous carbon dioxide and gaseous water . Suppose 64. g of hexane is mixed with 72.0 g of oxygen. Calculate the maximum mass of carbon dioxide that could be produced by the chemical reaction. Be sure your answer has the correct number of significant digits.
Answer:
45.7g of CO₂ is the maximum amount of carbon dioxide that could be produced.
Explanation:
Hexane, C₆H₁₄, reacts with O₂ to produce H₂O and CO₂ as follows:
C₆H₁₄ + 13/2O₂ → 7H₂O + 3CO₂
Where 1 mole of hexane reacts with 13/2 moles of O₂.
To solve this question we need to convert the mass of each reactant to moles in order to find the limiting reactant. With limiting reactant we can find the maximum amount of CO₂ produced:
Moles C₆H₁₄ -Molar mass: 86.18g/mol-:
64g C₆H₁₄ * (1mol / 86.18g) = 0.7426 moles C₆H₁₄
Moles O₂ -Molar mass: 32g/mol-:
72.0g O₂ * (1mol / 32g) = 2.25 moles O₂
For a complete reaction of 2.25 moles of O₂ are required:
2.25 moles O₂ * (1mol C₆H₁₄ / 13/2 moles O₂) = 0.346 moles of C₆H₁₄
As there are 0.7426 moles of C₆H₁₄, C₆H₁₄ is the excess reactant and:
Oxygen is limiting reactant.
The maximum moles of CO₂ that could be produced are:
2.25 moles O₂ * (3mol CO₂ / 13/2 moles O₂) = 1.038 moles CO₂
In grams:
1.038 moles CO₂ * (44.01g / mol) =
45.7g of CO₂ is the maximum amount of carbon dioxide that could be produced.Balance the equation
Answer:2NaF + Br2 —> 2NaBr + F2
2K + Cl2 —> 2KCl
N2+ 3F2 —> 2NF3
Explanation:
A radioactive substance has a half-life of 5 million years. What is the age of a rock in which 25% of the original radioactive atoms remain
Answer:
d. 10 million years
Explanation:
These are the options for the question
Choose one answer.
a. 2.5 million years
b. 5 million years
c. 15 million years
d. 10 million years
✓half-life of the radioactive substance= 5 million years
✓ Then for every 5 million years, original radioactive given (100%) percentage is reduced by factor of 1/2.
✓ 1st 5 million year; After the first 5 million years, the original radioactive is reduced as;
(100%) × 1/2 = 50% remains
✓2nd 5 million year: At 10 millions year, the 50% remaining radioactive is reduced by factor of 1/2
(50%) × 1/2 = 25% remains
Hence, at At 10 millions years 25% of the original radioactive atoms remain
.
Answer:
10 million years
In chemical reactions, elements tend to combine with other elements to____ stability and ____ total energy
Answer:
In chemical reactions, elements tend to combine with other elements to INCREASE_ stability and DECREASE total energy.
Explanation:
The chemical compounds when joining are more stable in external media such as solvents or solutions already formed, although this union with another chemical compound removes total energy from the compound.
What is an ecosystem? ?
Answer:
An ecosystem is a community or group of living organisms that live in and interact with each other in a specific environment.
Explanation:
That's the most straight forward explanation I could come up with
which would be a stronger acid H3PO4 or H3PO2
Answer:
h3po2
Explanation:
Answer:
i think it is H3PO4
Explanation:
Using your own words whats the difference between weather and climate
Answer:
Weather is at a specific place and time. Climate is over a period of time.
Explanation:
That is the difference