Eduqas Chemistry for A Level Year 2: Student Bk

Exam practice questions Component 1 1 Define the term oxidation. [1] 2 Show that the reaction between chlorine and Fe 2+ is a redox reaction. [2] 2Fe 2+ (aq) + Cl 2 (g) 2Fe 3+ (aq) + 2Cl – (aq) 3 Identify the oxidising agent in the reaction below, giving a reason for your answer. [1] 2Na (s) + Br 2 (g) 2Na Br (s) 4 Explain what is meant by the standard hydrogen electrode. [2] 5 Define the standard electrode potential. [2] 6 What is the function of the salt bridge? [1] 7 (a) Draw a diagram showing the apparatus required to measure the standard electrode potential for Ni 2+ (aq) ǀ Ni(s). [3] The standard electrode potential for this cell is given in the table below. (b) Label the direction of electron flow on your diagram. [1] (c) Label the positive electrode on your diagram. [1] 8 The table below gives standard electrode potentials , E q , for some systems for which the ion/electron half-equations are given. Half-equation E q / V Fe 2+ (aq) + 2e – Fe (s) –0.44 Ni 2+ (aq) + 2e – Ni (s) –0.25 H + (aq) + e – ½ H 2 (g) 0.00 Cu 2+ (aq) + 2e – Cu (s) 0.34 ½ I 2 (aq) + e – I – (aq) 0.54 Ag + (aq) + e – Ag (s) 0.80 Using the information from the table, answer the following questions: (a) State the strongest reducing agent. [1] (b) Find the EMF measured when the Fe 2+ (aq) ǀ Fe(s) and Ni 2+ (aq) ǀ Ni(s) are connected. [1] (c) State all the species that can be oxidised by aqueous iodine. [1] (d) State, giving a reason, whether you would expect a reaction to occur if a piece of nickel were placed in an aqueous solution of copper(II) sulfate. [2] (e) State, giving a reason, whether acid will corrode nickel metal. [2] PI1.1 91