Lawrie Ryan and Roger Norris Solutions for Chapter: Equilibria, Exercise 18: EXAM-STYLE QUESTIONS

Explain the effect on ${\mathrm{K}}_{\mathrm{c}}$ of an increase in pressure.

Explain the effect on ${\mathrm{K}}_{\mathrm{c}}$ of an increase in temperature.

When dissolved in an organic solvent, hydrogen chloride reacts with hydrogen iodide as follows: $\mathrm{HCl}+\mathrm{HI}\rightleftharpoons {\mathrm{H}}_2{\mathrm{Cl}}^{+}+{\mathrm{I}}^{-}$. Use the Bronsted-Lowry theory of acids and bases to explain which reactant is the acid, and which reactant is the base.

Sketch the graph of $\mathrm{pH}$ that would be obtained when $10.0 {\mathrm{cm}}^3$ of $0.200 \mathrm{mol} {\mathrm{dm}}^{-3} \mathrm{HCl}$ is titrated against $0.200 \mathrm{mol} {\mathrm{dm}}^{-3}$ aqueous ammonia.

Explain why methyl orange is a suitable indicator for strong acid-weak base titration but phenolphthalein is not.

Sketch the graph that would be obtained if $25.0 {\mathrm{cm}}^3$ of $0.200 \mathrm{mol} {\mathrm{dm}}^{-3}$ sodium hydroxide is titrated against $0.100 \mathrm{mol} {\mathrm{dm}}^{-3}$ ethanoic acid solution.

Explain why phenolphthalein is a suitable indicator for weak acid and strong base titration but methyl orange is not.

Bromocresol green and bromothymol blue are indicators. Bromocresol green has a $\mathrm{pH}$ range of $3.8$ to $5.4$ and bromothymol blue has a $\mathrm{pH}$ range of $6$ to $7.6$. Would either of these indicators be suitable for the titration in part $\mathrm{a}$ or the titration in part $\mathrm{c}$? Explain your answer.