Which of the following conditions will favour maximum formation of the product in the reaction, 
 $A_2 \left(g\right) + B_2 \left(g\right) \leftrightharpoons X_2 \left(g\right) {∆}_{r}H = -X k J$ ?

1. Low temperature and high pressure
2. Low temperature and low pressure
3. High temperature and high pressure
4. High temperature and low pressure

Consider the nitration of benzene using mixed conc. H₂SO₄ and HNO₃. If a large amount

of KHSO₄ is added to the mixture, the rate of nitration will be

1. slower 

2. unchanged

3. doubled

4. faster