Q: A $200.0\ \mathrm{g}$ solution contains $390\ \mathrm{mg}$ of sodium ion. What is the concentration in ppb?

$1.95 \times 10^6\ \mathrm{ppb}$

Q: Which calculation correctly converts $37.8\ \mathrm{g}$ of $CO_2$ to moles? ($CO_2$: $44.011\ \mathrm{g/mol}$)

$37.8\ \mathrm{g} \times \left(\frac{1\ \mathrm{mol}}{44.011\ \mathrm{g}}\right)$

Question 1

A chemist wants to produce 50.0 g of water by burning hydrogen gas in excess oxygen. The balanced equation is $2H_2(g) + O_2(g) \rightarrow 2H_2O(l)$. What mass of hydrogen gas is required?

Accepted Answer

$5.56\ \mathrm{g}$

Question 2

In the reaction $2KClO_3(s) \rightarrow 2KCl(s) + 3O_2(g)$, how many grams of $O_2$ are produced from $24.5\ \mathrm{g}$ of $KClO_3$? (Molar mass $KClO_3 = 122.55\ \mathrm{g/mol}$, $O_2 = 32.00\ \mathrm{g/mol}$)

Accepted Answer

$9.60\ \mathrm{g}$

Question 3

A plant consumes $44.0\ \mathrm{g}$ of $CO_2$ in photosynthesis. Using the balanced equation $6CO_2(g) + 6H_2O(g) \rightarrow C_6H_{12}O_6(aq) + 6O_2(g)$, what mass of glucose ($C_6H_{12}O_6$, molar mass $180.2\ \mathrm{g/mol}$) can be synthesized?

Accepted Answer

$30.0\ \mathrm{g}$

Question 4

Given the reaction $2NO(g) + 5H_2(g) \rightarrow 2NH_3(g) + 2H_2O(g)$, if you start with $60.0\ \mathrm{g}$ of $NO$ and $10.0\ \mathrm{g}$ of $H_2$, what is the limiting reagent?

Accepted Answer

$H_2$

Question 5

A reaction produces $15.0\ \mathrm{g}$ of product, but the theoretical yield is $20.0\ \mathrm{g}$. What is the percent yield?

Accepted Answer

$75\%$

Question 6

How many moles of $CO_2$ are produced when $5.00\ \mathrm{mol}$ of $C_8H_{18}(l)$ are burned according to $2C_8H_{18}(l) + 25O_2(g) \rightarrow 16CO_2(g) + 18H_2O(g)$?

Accepted Answer

$40.0\ \mathrm{mol}$

Question 7

If $100.0\ \mathrm{mL}$ of $0.250\ \mathrm{M}$ $NaCl$ solution is diluted to $400.0\ \mathrm{mL}$, what is the new concentration?

Accepted Answer

$0.0625\ \mathrm{M}$

Question 8

A $250.0\ \mathrm{g}$ solution contains $0.500\ \mathrm{g}$ of $KNO_3$. What is the concentration in ppm?

Accepted Answer

$2000\ \mathrm{ppm}$

Question 9

In the reaction $Fe_2O_3(s) + 3CO(g) \rightarrow 2Fe(s) + 3CO_2(g)$, $167\ \mathrm{g}$ of $Fe_2O_3$ reacts with $85.8\ \mathrm{g}$ of $CO$. What is the theoretical yield of iron ($Fe$) in grams? ($Fe_2O_3$: $159.7\ \mathrm{g/mol}$, $CO$: $28.011\ \mathrm{g/mol}$, $Fe$: $55.85\ \mathrm{g/mol}$)

Accepted Answer

$114\ \mathrm{g}$

Question 10

A $100.0\ \mathrm{mL}$ solution contains $0.250\ \mathrm{g}$ of $NaCl$. What is the mass/volume percent ($\%$ m/v) of $NaCl$ in the solution?

Accepted Answer

$2.5\%$

Question 11

Which of the following best explains why the actual yield of a chemical reaction is often less than the theoretical yield?

Accepted Answer

Side reactions, reversibility, and product recovery issues reduce the actual yield.

Question 12

A $200.0\ \mathrm{g}$ solution contains $390\ \mathrm{mg}$ of sodium ion. What is the concentration in ppb?

Accepted Answer

$1.95 	imes 10^6\ \mathrm{ppb}$

Question 13

If $25.0\ \mathrm{g}$ of $CH_4$ reacts with $80.0\ \mathrm{g}$ of $O_2$ according to $CH_4 + 2O_2 \rightarrow CO_2 + 2H_2O$, what is the limiting reagent? ($CH_4$: $16.04\ \mathrm{g/mol}$, $O_2$: $32.00\ \mathrm{g/mol}$)

Accepted Answer

$O_2$

Question 14

A $0.500\ \mathrm{L}$ solution contains $0.0250\ \mathrm{mol}$ of $KBr$. What is the molarity of the solution?

Accepted Answer

$0.0500\ \mathrm{M}$

Question 15

You have $100.0\ \mathrm{mL}$ of $0.500\ \mathrm{M}$ $HCl$ and want to dilute it to $0.100\ \mathrm{M}$. What will be the final volume after dilution?

Accepted Answer

$500.0\ \mathrm{mL}$

Question 16

A solution is prepared by dissolving $5.00\ \mathrm{g}$ of $NaOH$ in enough water to make $250.0\ \mathrm{mL}$ of solution. What is the molarity of the solution? ($NaOH$: $40.00\ \mathrm{g/mol}$)

Accepted Answer

$0.500\ \mathrm{M}$

Question 17

In the reaction $3H_2(g) + N_2(g) \rightarrow 2NH_3(g)$, what is the theoretical yield of $NH_3$ (in kg) from $5.22\ \mathrm{kg}$ of $H_2$ and $31.5\ \mathrm{kg}$ of $N_2$? ($H_2$: $2.02\ \mathrm{g/mol}$, $N_2$: $28.02\ \mathrm{g/mol}$, $NH_3$: $17.03\ \mathrm{g/mol}$)

Accepted Answer

$44.0\ \mathrm{kg}$

Question 18

A $500.0\ \mathrm{mL}$ solution contains $2.00\ \mathrm{g}$ of $KCl$. What is the mass/volume percent ($\%$ m/v) of $KCl$?

Accepted Answer

$0.40\%$

Question 19

Which calculation correctly converts $37.8\ \mathrm{g}$ of $CO_2$ to moles? ($CO_2$: $44.011\ \mathrm{g/mol}$)

Accepted Answer

$37.8\ \mathrm{g} 	imes \left(\frac{1\ \mathrm{mol}}{44.011\ \mathrm{g}}ight)$

Stoichiometry and Solution Concentrations: Mass Relationships in Chemical Reactions

Study Guide - Practice Questions

Study Guide - Flashcards