Given that the van der Waals constant 'a' (in L2 atm mol−2) for NH3, H2, O2 and CO2 are respectively 4.17, 0.244, 1.36 and 3.59, which one of the following gases is most easily liquefied?

Which of the following territories was annexed by Lord Dalhousie under the pretext of misgovernance, and not directly through the Doctrine of Lapse?

What was the primary stated reason for the Partition of Bengal in 1905 by Lord Curzon?