Chemical equilibrium | Practice Problems, Examples & Solutions

Concept

General Chemistry: Principles and Modern Applications

For the reaction $\mathrm{SO}_{2}(\mathrm{g}) \rightleftharpoons \mathrm{SO}_{2}(\mathrm{aq}), K=1.25 \mathrm{at}$
$25^{\circ} \mathrm{C} .$ Will the amount of $\mathrm{SO}_{2}(\mathrm{g})$ be greater than or less than the amount of $\mathrm{SO}_{2}(\mathrm{aq}) ?$

Principles of Chemical Equilibrium

02:20

General Chemistry: Principles and Modern Applications

For the synthesis of ammonia at $500 \mathrm{K}, \mathrm{N}_{2}(\mathrm{g})+$ $3 \mathrm{H}_{2}(\mathrm{g}) \rightleftharpoons 2 \mathrm{NH}_{3}(\mathrm{g}), K_{p}=9.06 \times 10^{-2}$ when the
pressures are expressed in atmospheres. Assume that $\mathrm{N}_{2}$ and $\mathrm{H}_{2}$ are mixed in the mole ratio 1: 3 and that the total pressure is maintained at 1.00 atm. What is the mole percent $\mathrm{NH}_{3}$ at equilibrium? [Hint: Use the equation from Exercise $87 .]$

Principles of Chemical Equilibrium

03:53

General Chemistry: Principles and Modern Applications

The $\mathrm{N}_{2} \mathrm{O}_{4}-\mathrm{NO}_{2}$ equilibrium mixture in the flask on the left in the figure is allowed to expand into the evacuated flask on the right. What is the composition of the gaseous mixture when equilibrium is re-established in the system consisting of the two flasks?
$$\mathrm{N}_{2} \mathrm{O}_{4}(\mathrm{g}) \rightleftharpoons 2 \mathrm{NO}_{2}(\mathrm{g}) \quad K_{c}=4.61 \times 10^{-3} \mathrm{at}\ 25^{\circ} \mathrm{C}$$

Principles of Chemical Equilibrium

Equilibrium Constant

313 Practice Problems

03:06

Shriver & Atkins’ Inorganic Chemistry

Using hard-soft concepts, which of the following reactions are predicated to have an equilibrium constant greater than 1 ? Unless otherwise stated, assume gas-phase or hydrocarbon solution and $25^{\circ} \mathrm{C}$
(a) $\mathrm{R}_{3} \mathrm{PBBr}_{3}+\mathrm{R}_{3} \mathrm{NBF}_{3} \rightleftharpoons \mathrm{R}_{3} \mathrm{PRBF}_{3}+\mathrm{R}_{3} \mathrm{NBBr}_{3}$
(b) $\mathrm{SO}_{2}+\left(\mathrm{C}_{6} \mathrm{H}_{5}\right)_{3} \mathrm{P}: \mathrm{HOC}\left(\mathrm{CH}_{3}\right)_{3} \rightleftharpoons\left(\mathrm{C}_{6} \mathrm{H}_{5}\right)_{3} \mathrm{PSO}_{2}+\mathrm{HOC}\left(\mathrm{CH}_{3}\right)_{3}$
(c) $\mathrm{CH}_{3} \mathrm{HgI}+\mathrm{HCl} \rightleftharpoons \mathrm{CH}_{3} \mathrm{HgCl}+\mathrm{HI}$
(d) $\left[\mathrm{AgCl}_{2}\right]^{2-(\mathrm{aq})}+2 \mathrm{CN}^{-}(\mathrm{aq}) \rightleftharpoons\left[\mathrm{Ag}(\mathrm{CN})_{2}\right]^{-(a q)}+2 \mathrm{Cl}^{-(a q)}$

Acids and bases

06:47

Chemistry: Introducing Inorganic, Organic and Physical Chemistry

Identify the acid, base, conjugate acid, and conjugate base in the following equilibrium. (Section 7.1).
(a) $\mathrm{HCO}_{2} \mathrm{H}(\mathrm{aq})+\mathrm{H}_{2} \mathrm{O}\left(\mathrm{j} \rightleftharpoons \mathrm{HCO}_{2}^{-}(\mathrm{aq})+\mathrm{H}_{3} \mathrm{O}^{+}(\mathrm{aq})\right.$
(b) $\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{NH}_{2}(\mathrm{aq})+\mathrm{H}_{2} \mathrm{O}(\mathrm{l}) \rightleftharpoons \mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{NH}_{3}^{+}(\mathrm{aq})+\mathrm{OH}^{-(\mathrm{aq})}$
(c) $\mathrm{H}_{2} \mathrm{SO}_{4}+\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{OH} \rightleftharpoons \mathrm{HSO}_{4}^{-}+\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{OH}_{2}^{+}$

Acids and bases

10:08

Physical Chemistry

At 1273 K and at a total pressure of 30.4 bar the equilibrium in the reaction $\mathrm{CO}_{2}(\mathrm{g})+\mathrm{C}(\mathrm{s})=2 \mathrm{CO}(\mathrm{g})$ is such that 17
mol $\%$ of the gas is $\mathrm{CO}_{2}$. $(a)$ What percentage would be $\mathrm{CO}_{2}$ if the total pressure were 20.3 bar? ( $b$ ) What would be the effect on the equilibrium of adding $\mathrm{N}_{2}$ to the reaction mixture in a closed vessel until the partial pressure of $\mathrm{N}_{2}$ is 10 bar? $(c)$ At what pressure of the reactants will $25 \%$ of the gas be $\mathrm{CO}_{2} ?$

Chemical Equilibrium

Le Châtelier’s Principle

95 Practice Problems

06:31

Chemistry

The formation of $\mathrm{SO}_{3}$ from $\mathrm{SO}_{2}$ and $\mathrm{O}_{2}$ is an intermediate step in the manufacture of sulfuric acid, and it is also responsible for the acid rain phenomenon. The equilibrium constant $K_{P}$ for the reaction
$$2 \mathrm{SO}_{2}(g)+\mathrm{O}_{2}(g) \rightleftharpoons 2 \mathrm{SO}_{3}(g)$$
is 0.13 at $830^{\circ} \mathrm{C}$. In one experiment, $2.00 \mathrm{mol} \mathrm{SO}_{2}$ and $2.00 \mathrm{mol}$
$\mathrm{O}_{2}$ were initially present in a flask. What must the total pressure at equilibrium be in order to have an 80.0 percent yield of $\mathrm{SO}_{3}$ ?

Chemical Equilibrium

01:49

Chemistry

Use Le Châtelier's principle to explain how the common ion effect affects the $\mathrm{pH}$ of a weak acid solution.

Acid-Base Equilibria and Solubility Equilibria

15:23

General Chemistry: Principles and Modern Applications

In one of Fritz Haber's experiments to establish the conditions required for the ammonia synthesis reaction, pure $\mathrm{NH}_{3}(\mathrm{g})$ was passed over an iron catalyst at $901^{\circ} \mathrm{C}$ and 30.0 atm. The gas leaving the reactor was bubbled through $20.00 \mathrm{mL}$ of a $\mathrm{HCl}($ aq) solution. In this way, the $\mathrm{NH}_{3}(\mathrm{g})$ present was removed by reaction with HCl. The remaining gas occupied a volume of $1.82 \mathrm{L}$ at $0^{\circ} \mathrm{C}$ and 1.00 atm. The $20.00 \mathrm{mL}$ of $\mathrm{HCl}(\mathrm{aq})$
through which the gas had been bubbled required $15.42 \mathrm{mL}$ of $0.0523 \mathrm{M} \mathrm{KOH}$ for its titration. Another $20.00 \mathrm{mL}$ sample of the same $\mathrm{HCl}(\mathrm{aq})$ through which no gas had been bubbled required $18.72 \mathrm{mL}$ of $0.0523 \mathrm{M}$ KOH for its titration. Use these data to obtain a value of $K_{p}$ at $901^{\circ} \mathrm{C}$ for the reaction $\mathrm{N}_{2}(\mathrm{g})+3 \mathrm{H}_{2}(\mathrm{g}) \rightleftharpoons$
$2 \mathrm{NH}_{3}(\mathrm{g})$

Principles of Chemical Equilibrium