Most of the world’s chlorine and sodium hydroxide are obtained through the electrolysis of brine: NaC1 (aq) + H₂O (1) → ½ H₂ (g) + ½ C1₂ (g) + NaOH (aq)

(a) Determine the standard heats of formation of NaC1 (aq) and NaOH (aq) and then the standard heat of the brine electrolysis reaction. The standard heat of solution of NaC1 is ΔH_s (r = ∞) = + 4.87 kJ/mol NaC1.

(b) Several years ago, the annual production of chlorine in the United States was roughly 8500 metric kilotons. Calculate the energy requirement in MW ∙ h/yr corresponding to this production rate, assuming that all of the chlorine is produced by electrolysis at 25°C and the required energy input equals ΔH for the process.