According to the following diagram, A reduces BO₂ when the temperature is :

A chemist has 4 samples of artificial sweetener A, B, C and D. To identify these samples, he performed certain experiments and noted the following observations :

(i) A and D both form blue-violet colour with ninhydrin.

(ii) Lassaigne extract of C gives positive AgNO₃ test and negative Fe₄[Fe(CN)₆]₃ test.

(iii) Lassaigne extract of B and D gives positive sodium nitroprusside test

Based on these observations which option is correct ?

'X' melts at low temperature and is a bad conductor of electricity in both liquid and solid state. X is :

If enthalpy of atomisation for Br₂₍₁₎ is x kJ/mol and bond enthalpy for Br₂ is y kJ/mol, the relation between them :