Honors Chemistry
Study Guide: Unit 5
This study guide is an overview of Unit 1 material. Please answer all of the questions to prepare for the unit test. We will work any problems you have questions about before the unit test.
All notes, BR, classwork, homework, and labs are fare game questions for the unit test.
________________________________________________________________________________
Notes

Stoichiometry

Mole Conversions

Percent Composition

Empirical vs Molecular Formula

Heat Transfer

Gas Laws

Study Unit 5 Vocabulary
Stoichiometry
1. Define Stoichiometry
2. What is a mole?
3. What is Avogadro’s Number?
4. Draw the Mole Highway
5. 5.59 g iron = ____________ moles iron
6. 2.5 moles of hydrogen = _______________ grams hydrogen
7. 0.100 moles of a compound has a mass of 6.539 g. Formula mass = ___________
Percent Composition
8. What is percent composition?
9. Write the equation for percent composition.
10. List the steps for finding percent composition.
11. What is the percent composition of hydrogen and oxygen in hydrogen peroxide, H
2
O
2
?
Empirical vs Molecular Formula
12. Study Cheat Sheet
13. What is the difference between Empirical and Molecular formulas?
14. List the steps to find Empirical Formulas from percent’s of each element.
15. List the steps to find Molecular Formulas from an Empirical Formula.
Heat Transfer
16. The amount of energy required to raise the temp of 1 kg of material by 1 degree Kelvin is called?
17. The amount of energy required to convert solid at its melting point into a liquid without an increase in temperature is called?
18. The amount of heat required to convert a liquid into a gas without increasing the temperature is called?
19. In a heating and cooling diagram, what does a plateau show?
20. What is endothermic?
21. What is exothermic?
22. A device used to measure changes in thermal energy is called?

Gas Laws
23. What are the equations for Gas Law problems?
24. Upload Gas Laws Study Guide with Practice questions.
Review Questions
25. How many moles are in 325 grams of iron(III) sulfate, Fe
2
(SO
4
)
3
?
A. 0.467 mol
B. 0.812 mol
C. 1.23 mol
D. 2.14 mol
26. How many grams are in 1 mole of sulfuric acid (H
2
SO
4
)?
A.
0.01 × 10 –2
g
B. 0.02 × 10 –2 g
C. 4.9 × 10 1 g
D. 9.8 × 10 1 g
27. What is the percent by mass of sulfur in sulfur dioxide (SO
2
)?
A. 25%
B. 33%
C. 50%
D. 67%
28. Which compound has the greatest percent by mass of nitrogen?
A. NH
3
B. NF
3
C. NO
D. NO
2
29. Which represents an empirical formula?
A. C
6
H
12
O
6
B. N
2
O
4
C. H
2
SO
4
D. P
4
O
10
30. If the empirical formula for a compound is NO
2 and its molar mass is 92 g/mol, what is the molecular formula?
A. NO
B. NO
2
C. N
2
O
3
D. N
2
O
4
31. What would be the empirical formula of a compound that is 25.5% carbon, 6.40% hydrogen, and 68.1% oxygen?
A. CH
2
O
B. CH
3
O
2

C. C
2
H
3
O
2
D. C
4
HO
11
32. What is the percent composition of strontium (Sr) in strontium carbonate solid (SrCO
3
(s ))?
A. 1.68%
B. 20.0%
C. 56.3%
D. 59.4%
33. Carbon tetrachloride is a colorless liquid. How many molecules are present in 6.32 g of the compound?
A. 6.82 x 10 -26 molecules
B. 1.61 x 10 -21 molecules
C. 2.47 x 10 22 molecules
D. 5.85 x 10 26 molecules
34. What is the percentage of water present in nickel(II) chloride hexahydrate, NiCl
2
-6H
2
O?
A. 7.58%
B. 13.9%
C. 45.5%
D. 83.4%
35. In an experiment, Guy gently heated a hydrated copper compound to remove the water of hydration. If the compound originally weighed 1.72 g before heating and weighed 1.12 g after heating, what was the percentage of water in the compound?
A. 34.9%
B. 46.5%
C. 53.5%
D. 65.1%
36. How many moles of CO are present in a volume of 1.00 L at STP?
A. 0.0446 mol
B. 0.224 mol
C. 22.4 mol
D. 28.0 mol
37. What volume would a 10.0 mole sample of helium gas occupy at STP?
A. 0.446 L
B. 4.46 L
C. 2.24 L
D. 224 L

38. Which of the following is false about the molecule above?
A. As a liquid, It is soluble in water
B. It has a tetrahedral shape
C. It has a low boiling point
D. The IUPAC name is carbon tetrahydride
39. Which process involves a decrease in kinetic energy?
A. A. freezing
B. B. melting
C. C. sublimation
D. D. vaporization
40. A 50 g piece of iron at 298 K is placed into 250 mL of water at 363 K in an insulated container. Which BEST describes and explains what will occur.
A. A. The kinetic energy of the water will increase as heat is transferred from the piece of iron to the water.
B. B. The kinetic energy of the water will decrease as heat is transferred from the water to the piece of iron.
C. C. The temperature of the water will decrease as cold is absorbed from the iron.
D. D. The temperature of the iron will increase as cold is released into the water.
41. A heating curve for a pure substance is shown:
Which is the boiling point for this substance?
A. A.
30°C
B. B.
70°C
C. C. 140°C
D. D. 180°C
42. Ten grams of water undergo a temperature change from 15.0°C to 0°C. Which explains what has occurred?
A. A. 150 J of heat energy is lost
B. B. 627 J of heat energy is lost

C. C. 150 J of heat energy is gained
D. D. 627 J of heat energy is gained
43. What quantity of heat is n eeded to raise the temperature of 100. g of iron from 25°C to
1535°C?
A. A. 19,500 J
B. B. 67,800 J
C. C. 68,900 J
D. D. 631,000 J
44. The heats of fusion and masses of several elements are shown.
Which element would require the most heat to melt for the mass listed?
A. Ag
B. Al
C. Cr
D. Cu
45.
How much energy is needed to bring 200. grams of water from 25.0°C to 90.0°C?
A. 20.9 kJ
B. 26.7 kJ
C. 54.3 kJ
D. 75.2 kJ
46. Which is the amount of heat needed to increase the temperature of 250 grams of water from
22°C to 67°C?
A.
1.1 × 10 4 J
B. 2.3 × 10 4 J
C. 4.7 × 10 4 J
D. 7.0 × 10 4 J
47. As the volume of a gas is reduced, the number of molecules…
A. increases
B. decreases
C. stays the same

D. is double
48. At STP 44.8L of CO
2
contains the same number of molecules as…
A. 1.0 mol of helium
B. 2.00 mol of nitrogen
C. 0.500 mol of hydrogen
D. 4.00 mole of nitrogen
49. The jars below each contain a different gas.
50.
If the three gases were mixed into one container, the pressure would be 260 atm. What is the pressure of the oxygen in the third jar?
A. A. 0.43 atm
B. B. 2.3 atm
C. C. 74 atm
D. D. 186 atm
51. Tim wants to store 0.122 moles of helium gas at 203 kPa and 401 K. Which is the volume of the helium gas needed for storage?
A. 0.240 L
B. B 0. 510 L
C. 2.00 L
D. 3.37L
52. Which temperature is the same as -13.0
0 C?
A. 260 K
B. 286 K
C. 747 K
D. 773 K
53. How many moles of gas are in a 5.0L container set at 1.0 atm and 25 0 C?
A. 25 mol
B. 0.20 mol
C. 1.93 mol

D. 1.25 mol
54. A gas is contained within a 0.75L tank at
760 mmHg. What would be the new pressure
if the volume is increased to 1.5L?
A. 380 mmHg
B. 1520 mmHg
C. 1100 mmHg
D. 675 mmHg
55. What is the new volume of a gas if the volume was 1400 mL when the temperature was 0 0 C and the temperature has been increased to 40 0 C?
A. 1221 mL
B. 1605 mL
C. 1554 mL
D. 1750 mL