2 Answer ALL the questions. Write your answers in the spaces provided. 1 This question is about chlorine. (a) Chlorine has two isotopes with mass numbers 35 and 37. (i) Complete the table to show the numbers of subatomic particles in a 35Cl atom and a 37Cl− ion. (2) Particle Protons Neutrons Electrons 35Cl atom 37Cl− ion (ii) A sample of chlorine contained 75 % of 35Cl and 25 % of 37Cl. Complete the mass spectrum to show the peaks you would expect for the molecular ion Cl2 + from this sample of chlorine gas. (2) 100 90 80 70 60 50 40 30 20 10 0 69 70 71 72 73 74 75 Relative abundance m / z Turn over 3 (b) Write the formula of potassium chlorate(V). (1) .................................................................................................................................................................................................................................................................................... (c) Write the equation for the first electron affinity of chlorine. Include state symbols. (2) (d) The standard electrode potential for the chlorine / chloride ion half-cell is ½Cl2(aq) + e− ⇌ Cl−(aq)  E O cell = +1.36 V (i) Identify an oxidising agent from the Data Booklet that will convert chloride ions into chlorine under standard conditions. (1) .................................................................................................................................................................................................................................................................................... (ii) Calculate the value of E O cell for the reaction in (d)(i). (1) (Total for Question 1 = 9 marks)