Arrange the following according to the instructions given in brackets: (a) C2H2, C3H6, CH4, C2H4 (In the increasing order of the molecular weight) (b) Cu2+, Na+, Zn2+, Ag+ (The order of Preferential discharge at the cathode)

Answer the following with reference to the electrolytic refining of copper: (a) What is used as the anode? (b) Where is pure copper deposited? (c) Write the cathode reaction.

Match the Column A with Column B: Column A Column B (a) Sodium chloride 1. has two shared pair of electrons (b) Methane 2. has high melting and boiling points (c) Hydrogen chloride gas 3. a greenhouse gas (d) Oxidation reaction 4. has low melting and boiling points (e) Water 5. Zn − 2e− ⟶ Zn2+ 6. S + 2e− ⟶ S2−

The following sketch illustrates the process of conversion of Alumina to Aluminium: [5] Study the diagram and answer the following: (a) Name the constituent of the electrolyte mixture which has a divalent metal in it. (b) Name the powdered substance ‘X’ sprinkled on the surface of the electrolyte mixture. (c) What is the name of the process? (d) Write the reactions taking place at the electrodes ‘Y’ (anode) and ‘Z’ (cathode) respectively.

X - HCl ⇋ H1+ + Cl- (in solution state) Y - PbBr2 ⇋ Pb2+ + 2Br1- (in molten state) From the above reactions X or Y, identify the reaction which exhibits: (a) electrolytic dissociation (b) ionization

Differentiate between the following pairs based on the criteria given in the bracket: (a) Acetic acid and Sulphuric acid (number of replaceable hydrogen ion per molecule) (b) Electrolyte and Metallic conductor (the particles conducting electricity)

Justify the following statements: (a) Anode is known as the oxidizing electrode. (b) Graphite electrodes are preferred in the electrolysis of molten lead bromide.

State the terms for the following: (a) The group obtained by removing one hydrogen atom from the parent alkane. (b) Two metal plates or wires through which the current enters and leaves the electrolytic cell. (c) The amount of substance which contains the same number of units as the number of atoms in carbon-12. (d) The tendency of an atom to pull a shared pair of electrons towards itself in a compound. (e) The formula which represents the simplest ratio between the atoms of elements present in a compound.

Complete the following sentences by choosing the correct answer from the brackets: (a) The salt that can be prepared by Direct Combination is ............... . [FeCl3 / FeCl2] (b) The metallic oxide which can be reduced by using common reducing agents is ............... . [Fe2O3 / Al2O3] (c) The metal nitrate which on thermal decomposition forms a black residue is ............... . [zinc nitrate / copper nitrate] (d) During the electrolysis of copper sulphate solution, if ............... is used as electrodes, the colour of the electrolyte does not fade. [copper / platinum] (e) The process of heating the concentrated ore in a limited supply or absence of air is ............... . [roasting / calcination]

The following sketch represents the electroplating of an Iron cup with Nickel metal. Study the diagram and answer the following questions: (a) During electroplating the iron cup is placed at the cathode. Why? (b) Name the ion that must be present in the electrolyte. (c) State one condition that is necessary to ensure that the deposit is smooth, firm and even. (d) Write the reaction taking place at the cathode. (e) What change would you observe at the anode?

K, L and M are beakers containing three different solutions as shown below. Name the beaker which: (a) contains only ions. (b) contains only molecules. (c) has pH less than 7.

Aqueous copper (II) sulphate is electrolysed using copper electrodes. Which statement about the electrolysis is not correct? (a) An oxidation reaction occurs at the positive electrode. (b) The current is carried through the electrolyte by ions. (c) The positive electrode loses mass. (d) The number of copper (II) ions in the electrolyte decreases.