A student found that $0.098 \mathrm{~g}$ of $\mathrm{PbF}_2$ was dissolved in 400 . $\mathrm{mL}$ of saturated $\mathrm{PbF}_2$. What is the $K_{\mathrm{sp}}$ for the lead(II) fluoride?

For the following equations, tell in which direction, left or right, the equilibrium will shift when these changes are made: The temperature is increased, the pressure is increased by decreasing the volume of the reaction vessel, and a catalyst is added.

(a) $2 \mathrm{~SO}_3(g)+197 \mathrm{~kJ} \rightleftharpoons 2 \mathrm{~SO}_2(g)+\mathrm{O}_2(g)$
(b) $4 \mathrm{~NH}_3(g)+3 \mathrm{~O}_2(g) \rightleftharpoons 2 \mathrm{~N}_2(g)+6 \mathrm{~H}_2 \mathrm{O}(g)+1531 \mathrm{~kJ}$
(c) $\mathrm{OF}_2(g)+\mathrm{H}_2 \mathrm{O}(g) \rightleftharpoons \mathrm{O}_2(g)+2 \mathrm{~HF}(g)+318 \mathrm{~kJ}$

Reactants $\mathrm{A}$ and $\mathrm{B}$ are mixed, cach initially at a concentration of $1.0~M$. They react to produce $\mathrm{C}$ according to this cquation:

$$2 \mathrm{~A}+\mathrm{B} \rightleftharpoons \mathrm{C}$$

When equilibrium is established, the concentration of $\mathrm{C}$ is found to be $0.30~M$. Calculate the value of $K_{\text {eq }}$.

Determine the $\mathrm{pH}$ for the following solutions:

(a) $5.0 \times 10^{-5}~M\mathrm{~HNO}_3$
(b) $2.0 \times 10^{-6}~M\mathrm{~KOH}$

Write the equilibrium constant expressions for these reactions:

(a) $3 \mathrm{O}_2(g) \rightleftharpoons 2 \mathrm{O}_3(g)$
(b) $\mathrm{H}_2 \mathrm{O}(g) \rightleftharpoons \mathrm{H}_2 \mathrm{O}(l)$
(c) $\mathrm{MgCO}_3(s) \rightleftharpoons \mathrm{MgO}(s)+\mathrm{CO}_2(g)$
(d) $2 \mathrm{~Bi}^{3+}(a q)+3 \mathrm{~H}_2 \mathrm{~S}(a q) \rightleftharpoons \mathrm{Bi}_2 \mathrm{S}_3(s)+6 \mathrm{~H}^{+}(a q)$

For the reaction $\mathrm{CO}(\mathrm{g})+\mathrm{H}_2 \mathrm{O}(\mathrm{g}) \rightleftharpoons \mathrm{CO}_2(\mathrm{~g})+\mathrm{H}_2(\mathrm{~g})$ at a certain temperature, $K_{\text {eq }}$ is 1 . At cquilibrium would you cxpect to find

(a) only $\mathrm{CO}$ and $\mathrm{H}_2$
(b) mostly $\mathrm{CO}_2$ and $\mathrm{H}_2$
(c) about equal concentrations of $\mathrm{CO}$ and $\mathrm{H}_2 \mathrm{O}$, compared to $\mathrm{CO}_2$ and $\mathrm{H}_2$
(d) mostly $\mathrm{CO}$ and $\mathrm{H}_2 \mathrm{O}$ (e) only $\mathrm{CO}$ and $\mathrm{H}_2 \mathrm{O}$ Explain your answer briefly.

One day in a laboratory, some water spilled on a table. In just a few minutes the water had evaporated. Some days later, a similar amount of water spilled again. This time, the water remained on the table after 7 or 8 hours. Name three conditions that could have changed in the lab to cause this difference.

Under certain circumstances, when oxygen gas is heated, it can be converted into ozone according to the following reaction equation:

$$3 \mathrm{O}_2(g)+\text { heat } \rightleftharpoons 2 \mathrm{~O}_3(g)$$

Name three different ways that you could increase the production of the ozone.

The solubility of $\mathrm{Hg}_2 \mathrm{I}_2$ in $\mathrm{H}_2 \mathrm{O}$ is $3.04 \times 10^{-7} \mathrm{~g} / \mathrm{L}$. The reaction $\mathrm{Hg}_2 \mathrm{I}_2 \rightleftharpoons \mathrm{Hg}_2^{2+}+2 \mathrm{~I}^{-}$represents the equilibrium. Calculate the $K_{\text {sp }}$.

The $K_{s p}$ of $\mathrm{SrSO}_4$ is $7.6 \times 10^{-7}$. Should precipitation occur when $25.0 \mathrm{~mL}$ of $1.0 \times 10^{-3} \mathrm{M} \mathrm{SrCl}_2$ solution are mixed with $15.0 \mathrm{~mL}$ of $2.0 \times 10^{-3}~M\mathrm{~Na}_2 \mathrm{SO}_4$ ? Show proof.

The $K_{\text {eq }}$ for the formation of ammonia gas from its elements is 4.0. If the equilibrium concentrations of nitrogen gas and hydrogen gas are both $2.0~M$, what is the equilibrium concentration of the ammonia gas?

For the following equations, tell in which direction, left or right, the equilibrium will shift when these changes are made: The temperature is increased, the pressure is increased by decreasing the volume of the reaction vessel, and a catalyst is added.

(a) $3\mathrm{~O}_2(\mathrm{~g})+271 \mathrm{~kJ} \rightleftharpoons 2 \mathrm{~O}_3(\mathrm{~g})$
(b) $\mathrm{CH}_4(\mathrm{~g})+\mathrm{Cl}_2(\mathrm{~g}) \rightleftharpoons \mathrm{CH}_3 \mathrm{Cl}(\mathrm{g})+\mathrm{HCl}(\mathrm{g})+110 \mathrm{~kJ}$
(c) $2 \mathrm{~NO}(\mathrm{g})+2 \mathrm{~H}_2(\mathrm{~g}) \rightleftharpoons \mathrm{N}_2(\mathrm{~g})+2 \mathrm{~H}_2 \mathrm{O}(\mathrm{g})+665 \mathrm{~kJ}$

If it takes $0.048 \mathrm{~g} \mathrm{~BaF}_2$ to saturate $15.0 \mathrm{~mL}$ of water, what is the $K_{s p}$ of $\mathrm{BaF}_2$ ?

Calculate the $K_{\mathrm{eq}}$ for the reaction

$$\mathrm{SO}_2(g)+\mathrm{O}_2(g) \rightleftharpoons \mathrm{SO}_3(g)$$

when the equilibrium concentrations of the gases at $530^{\circ} \mathrm{C}$ are $\left[\mathrm{SO}_3\right]=11.0~M,\left[\mathrm{SO}_2\right]=4.20~M$, and $\left[\mathrm{O}_2\right]=$ $0.60 \times 10^{-3}~M$