X, Y and Z are three crystalline solids which are soluble in water and have a common anion. To help you to identify X, Y and Z, you are provided with the following experimental observations. Copy and complete the corresponding inferences in (a) to (e). (a) A reddish-brown gas is obtained when X, Y and Z are separately warmed with concentrated sulphuric acid and copper turning added to the mixture. INFERENCE 1 : The common anion is the .................. ion. (b) When X is heated, it melts and gives off only one gas which re-lights a glowing splint. INFERENCE 2 : The cation in X is either ................ or .................... (c) The action of heat on Y produces a reddish-brown gas and a yellow residue which fuses with the glass of the test tube. INFERENCE 3 : The metal ion present in Y is the .................... ion. (d) When Z is heated, it leaves no residue. Warming Z with sodium hydroxide solution liberates a gas which turns moist red litmus paper blue. INFERENCE 4 : Z contans the ............ cation. (e) Write the equations for the following reactions: (1) X and concentrated sulphuric acid (below 200∘). (One equation only for either of the cations given in INFERENCE 2). (2) Action of heat on Y. (3) Concentrated nitric acid is added to copper turnings kept in a beaker.