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 (f).
(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 contains the ……………. Cation.
(e) Write the equations for the following reactions:
(1) X and concentrated sulphuric acid (below 200° C). (One equation only for either of the cations given in INFERENCE 2).
(2) The action of heat on Y.
(3) Concentrated nitric acid is added to copper turnings kept in a beaker.
