During municipal water treatment and in outdoor swimming pools, chlorine is added to sanitise water. However, in the presence of sunlight (UV radiation), chlorine undergoes a rapid photochemical reaction with water rather than forming the weak acid responsible for disinfection.
Which equation correctly represents this decomposition reaction of chlorine in water in the presence of sunlight?
Cl2(aq)+H2O(l)⇌HClO(aq)+HCl(aq)Cl_2(aq) + H_2O(l) \rightleftharpoons HClO(aq) + HCl(aq)Cl2(aq)+H2O(l)⇌HClO(aq)+HCl(aq)
2Cl2(aq)+H2O(l)→2HCl(aq)+Cl2O(aq)2Cl_2(aq) + H_2O(l) \rightarrow 2HCl(aq) + Cl_2O(aq)2Cl2(aq)+H2O(l)→2HCl(aq)+Cl2O(aq)
2Cl2(aq)+2H2O(l)→4HCl(aq)+O2(g)2Cl_2(aq) + 2H_2O(l) \rightarrow 4HCl(aq) + O_2(g)2Cl2(aq)+2H2O(l)→4HCl(aq)+O2(g)
Cl2(aq)+H2O(l)→2HCl(aq)+O(g)Cl_2(aq) + H_2O(l) \rightarrow 2HCl(aq) + O(g)Cl2(aq)+H2O(l)→2HCl(aq)+O(g)
Practise OCR GCSE Chemistry Interpreting and interacting with earth systems with exam-style questions for Foundation and Higher tier. 49 questions, matched to the OCR GCSE Chemistry (J248) specification and written in Paper 1 and Paper 2 (Foundation Tier) or Paper 3 and Paper 4 (Higher Tier) style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.