Chemistry Benchmark Test

1. Fe₂O₃ + 3CO -> 2Fe + 3CO₂ In this reaction how many grams of Fe₂O₃ are required to completely react with 84 grams of CO?

a. 64 g

b. 80g

c. 160g

d. 1400g

2. How many moles of CH₄ are contained in 96 grams of CH₄?

a. 3.00 moles

b. 6.00 moles

c. 12.0 moles

d. 16.0 moles

3. How many atoms are in a chromium sample with a mass of 13 grams?

a. 1.6 x 10²³

b. 3.3 x 10²³

c. 19 x 10²⁶

d. 24 x 10²⁴

4. C₃H₈ + 0₂ -> CO₂ + H₂O This chemical equation represents the combustion of propane. When correctly balanced, the coefficient for water is

a. 2

b. 4

c. 8

d. 16

5. How many moles of carbon-12 are contained in exactly 6 grams of carbon-12?

a. 0.5 mole

b. 20 moles

c. 3.01 x 10 ²³

d. 6.01 x 10²³

6. _NH₃ (g) + _O₂ (g) -> N₂ (g) + _H₂O (g) is a chemical equation. When the equations is completely balanced, the coefficient for NH₃ will be

a. 2

b. 3

c. 4

d. 6

7. How many atoms are contained in 97.6 g of platinum (Pt)?

a. 0.1 x 10³⁰

b. 3.01 x ²³

c. 1.0 x 10²³

d. 11.0 x 10⁸

8. Which of the following is a balanced equation for the combustion of ethanol

a. CH₃CH₂OH + 3O₂ -> CO₂ +2H₂O

b. CH₃CH₂OH + 3O₂ -> 2CO₂ +3H₂O

c. CO₂ +2H₂O + O₂ -> 2CO₂ +3HO

d. CO₂ +2H₂O + 2O₂ -> 3CO₂ +2H₂O

e.

9. A mass of 5.4 grams of aluminum (Al) reacts with an excess of copper (II) chloride (CuCl₂) in solution as shown in the equation 3CuCl₂ + 2Al -> 2AlCl₃ + 3Cu. What mass of solid copper (Cu) is produced

a. 0.65 g

b. 8.5 g

c. 13 g

d. 19 g

10. How many moles of chlorine gas are contained in 9.02 x 10²³ molecules?

a. 1.5 moles

b. 2.0 moles

c. 6.02 moles

d. 9.03 moles

Answer key

1. c

2. b

3. a

4. b

5. a

6. c

7. b

8. b

9. d

10. a