The $${\left( {{{\partial E} \over {\partial T}}} \right)_P}$$ of different types of half cells are as follows:

(Where E is the electromotive force)

Which of the above half cells would be preferred to be used as reference electrode?

Choose the correct stability order of group 13 elements in their + 1 oxidation state :

Given below are two statements :

Statement I : In 'Lassaigne's Test', when both nitrogen and sulphur are present in an organic compound, sodium thiocyanate is formed.

Statement II : If both nitrogen and sulphur are present in an organic compound, then the excess of sodium used in sodium fusion will decompose the sodium thiocyanate formed to give NaCN and Na₂S.

In the light of the above statements, choose the most appropriate answer from the options given below :

(C₇H₅O₂)₂ $$\buildrel {hv} \over \longrightarrow $$ [X] $$\to$$ 2C₆H₅ + 2CO₂

Consider the above reaction and identify the intermediate 'X'