The metal mainly used in devising photoelectric cells is :

The increasing order of the following compounds towards HCN addition is :

The Gibbs change (in J) for the given reaction at
[Cu²⁺] = [Sn²⁺] = 1 M and 298K is :

Cu(s) + Sn²⁺(aq.) $$ \to $$ Cu²⁺(aq.) + Sn(s);

($$E_{S{n^{2 + }}|Sn}^0 = - 0.16\,V$$,
$$E_{C{u^{2 + }}|Cu}^0 = 0.34\,V$$)
Take F = 96500 C mol^–1)

The mass of gas adsorbed, x, per unit mass of adsorbate, m, was measured at various pressures, p. A graph between $$\log {x \over m}$$ and log p gives a straight line with slope equal to 2 and the intercept equal to 0.4771. The value of $${x \over m}$$ at a pressure of 4 atm is :
(Given log 3 = 0.4771)