DAT General Chemistry: Stoichiometry 2

Question 1

How many moles of oxygen gas are required to completely combust 2 moles of propane (C3H8)?

Accepted Answer

10 mol

Answer

5 mol

Answer

3 mol

Answer

8 mol

Question 2

What is the percent composition by mass of carbon in CO2 (C=12, O=16)?

Accepted Answer

27.3%

Answer

50.0%

Answer

72.7%

Answer

12.0%

Question 3

If 3 mol of N2 react with 6 mol of H2, which is the limiting reagent in N2 + 3H2 → 2NH3?

Accepted Answer

H2

Answer

N2

Answer

Neither, exactly stoichiometric

Answer

NH3

Question 4

How many grams are in 0.50 mol of NaCl (Na=23, Cl=35.5)?

Accepted Answer

29.25 g

Answer

58.5 g

Answer

14.6 g

Answer

117 g

Question 5

What is the empirical formula of a compound that is 40% C, 6.7% H, and 53.3% O by mass?

Accepted Answer

CH2O

Answer

CHO

Answer

C2H4O2

Answer

CH4O

Question 6

How many molecules are in 2.0 mol of water?

Accepted Answer

1.2 × 10^24

Answer

6.02 × 10^23

Answer

3.01 × 10^23

Answer

1.2 × 10^23

Question 7

In the reaction 2H2 + O2 → 2H2O, how many grams of water form from 4 g of H2 (excess O2, H=1, O=16)?

Accepted Answer

36 g

Answer

18 g

Answer

72 g

Answer

9 g