At constant volume, 4 mol of an ideal gas when heated from 300 K to 500K changes its internal energy by 5000 J. The molar heat capacity at constant volume is _______.

In the following sequence of reactions the maximum number of atoms present in molecule 'C' in one plane is _________. (A is a lowest molecular weight alkyne)

The major product [B] in the following sequence of reactions is :-

Among the compounds A and B with molecular formula C₉H₁₈O₃ , A is having higher boiling point the B. The possible structures of A and B are :