Match the terms in Column-I with their description in Column-II:
Column-I Column-II (P) N2O5 (i) N–N bond (Q) N2O (ii) N–O–N bond (R) N2O4 (iii) N=N / NN bond (S) NO2 (iv) N=O bond
P – (ii), Q – (iii), R – (i), S – (iv)
Method used for separation of mixture of products (B and C) obtained in the following reaction is: 
Which one of the following graphs accurately represents the plot of partial pressure of CS₂ vs its mole fraction in a mixture of acetone and CS₂ at constant temperature?

In the given figure, the blocks $A$, $B$ and $C$ weigh $4\,\text{kg}$, $6\,\text{kg}$ and $8\,\text{kg}$ respectively. The coefficient of sliding friction between any two surfaces is $0.5$. The force $\vec{F}$ required to slide the block $C$ with constant speed is ___ N.
(Given: $g = 10\,\text{m s}^{-2}$) 