For an electrochemical cell

Sn(s) | Sn²⁺ (aq,1M)||Pb²⁺ (aq,1M)|Pb(s)

the ratio $${{\left[ {S{n^{2 + }}} \right]} \over {\left[ {P{b^{2 + }}} \right]}}$$ when this cell attains equilibrium is _________.

(Given $$E_{S{n^{2 + }}|Sn}^0 = - 0.14V$$,

$$E_{P{b^{2 + }}|Pb}^0 = - 0.13V$$, $${{2.303RT} \over F} = 0.06$$)

The correct order of the calculated spin-only magnetic moments of complexs (A) to (D) is:
(A) Ni(CO)₄
(B) [Ni(H₂O)₆]Cl₂
(C) Na₂[Ni(CN)₄]
(D) PdCl₂(PPh₃)₂

Hydrogen has three isotopes (A), (B) and (C). If the number of neutron(s) in (A), (B) and (C) respectively, are (x), (y) and (z), the sum of (x), (y) an (z) is :

The major product in the following reaction is: