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 :

A process has $$\Delta $$H = 200 J mol^–1 and $$\Delta $$S = 40 JK^–1 mol^–1. Out of the values given below, choose the minimum temperature above which the process will be spontaneous :

Which hydrogen in compound (E) is easily replaceable during bromination reaction in presence of light ?

A mixture of 100 m mol of Ca(OH)₂ and 2 g of sodium sulphate was dissolved in water and the volume was made up to 100 mL. The mass of calcium sulphate formed and the concentration of OH^– in resulting solution, respectively, are : (Molar mass of Ca (OH)₂, Na₂SO₄ and CaSO₄ are 74, 143 and 136 g mol^–1 , respectively; K_sp of Ca(OH)₂ is 5.5 × 10^–6 )