Chapter 3 — Stoichiometry

Section 3.4 — Mass Relationships and Limiting Reagents

Problems

1

Calculate the molar mass of ammonium sulfate, $\ce{(NH4)2SO4}$. Report your answer to four significant figures.

2

How many moles are present in $\pu{45.0 g}$ of glucose, $\ce{C6H12O6}$?

3

Balance the following equation:

$\ce{C3H8 + O2 -> CO2 + H2O}$

4

How many molecules of $\ce{CO2}$ are produced when $\pu{2.50 mol}$ of propane burns completely?

5

Iron(III) oxide reacts with carbon monoxide:

$\ce{Fe2O3 + 3CO -> 2Fe + 3CO2}$

What mass of iron is produced from $\pu{125 g}$ of $\ce{Fe2O3}$?

6

$\pu{10.0 g}$ of $\ce{H2}$ reacts with $\pu{64.0 g}$ of $\ce{O2}$. Which is the limiting reagent?

7

$\pu{25.0 g}$ of $\ce{N2}$ reacts with $\pu{5.00 g}$ of $\ce{H2}$ to form ammonia:

$\ce{N2 + 3H2 -> 2NH3}$

Determine the limiting reagent and the theoretical yield of $\ce{NH3}$ in grams.

8

A reaction with a theoretical yield of $\pu{18.6 g}$ produces $\pu{15.2 g}$ of product. Calculate the percent yield.

9

A sample of $\ce{CaCO3}$ has a mass of $\pu{0.4820 g}$. How many formula units does it contain? Report to the correct number of significant figures.

10

$\pu{15.0 g}$ of $\ce{Al}$ reacts with $\pu{75.0 g}$ of $\ce{Fe2O3}$ in a thermite reaction. If $\pu{22.1 g}$ of iron is recovered, what is the percent yield?