Concentrated hydrochloric acid, HCl(aq)\text{HCl(aq)}HCl(aq), can be electrolysed using inert electrodes.
Write a balanced ionic half-equation for the formation of hydrogen gas, H2\text{H}_2H2, at the negative electrode (cathode).
During the electrolysis, a volume of 36 cm3 of chlorine gas, Cl2\text{Cl}_2Cl2, is collected at the positive electrode (anode).
Calculate the amount, in moles, of chlorine gas in 36 cm3. (The volume of 1 mol of any gas at room temperature and pressure is 24 000 cm324\,000\text{ cm}^324000 cm3.)
Calculate the quantity of electricity, in coulombs, needed to produce this volume of chlorine gas from the half-equation:
2Cl−→Cl2+2e− 2\text{Cl}^- \rightarrow \text{Cl}_2 + 2\text{e}^- 2Cl−→Cl2+2e−(1 faraday=96 500 coulombs1\text{ faraday} = 96\,500\text{ coulombs}1 faraday=96500 coulombs)
Chlorine gas reacts with potassium iodide solution. The equation for this reaction is:
Cl2(g)+2I−(aq)→2Cl−(aq)+I2(aq) \text{Cl}_2(\text{g}) + 2\text{I}^-(\text{aq}) \rightarrow 2\text{Cl}^-(\text{aq}) + \text{I}_2(\text{aq}) Cl2(g)+2I−(aq)→2Cl−(aq)+I2(aq)This reaction can be described as both a displacement reaction and a redox reaction.
Identify the element that is displaced in this reaction.
Explain why this reaction is described as a redox reaction in terms of electron transfer.
Chlorine is also used in the industrial manufacture of sulfuryl chloride, SO2Cl2\text{SO}_2\text{Cl}_2SO2Cl2. The equation for this reaction is:
SO2(g)+Cl2(g)⇌SO2Cl2(g)ΔH=−84 kJ/mol \text{SO}_2(\text{g}) + \text{Cl}_2(\text{g}) \rightleftharpoons \text{SO}_2\text{Cl}_2(\text{g}) \quad \Delta H = -84\text{ kJ/mol} SO2(g)+Cl2(g)⇌SO2Cl2(g)ΔH=−84 kJ/molWhat does the ⇌ \rightleftharpoons\,⇌ symbol indicate about this reaction?
Predict and explain the effect of increasing the temperature on the equilibrium position of this reaction.
