Consider the following reduction processes :
Zn²⁺ + 2e^– $$ \to $$ Zn(s) ; E^o = – 0.76 V
Ca²⁺ + 2e^– $$ \to $$ Ca(s); E^o = –2.87 V
Mg²⁺ + 2e^– $$ \to $$ Mg(s) ; E^o = – 2.36 V
Ni² + 2e^– $$ \to $$ Ni(s) ; E^o = – 0.25
The reducing power of the metals increases in the order :

The major product formed in the reaction given below will be :

Liquids A and B form an ideal solution in the entire composition range. At 350 K, the vaapor pressures of pure A and pure B are 7 $$ \times $$ 10³ Pa and 12 $$ \times $$ 10³ Pa, respectively . The composition of the vapor in equilibriumwith a solution containing 40 mole percent of A at this temperature is :

The effect of lanthanoid contraction in the lanthanoid series of elements by and large means :