JEE MAINS CHEMISTRY QUESTION SEPTEMBER 2020
Answers
For the following reaction at equilibrium
2NO₂ (g)⇔N₂O₄ (g) , ∆H = - 58kJ/mole
following change are made then identify in which direction reaction shift.
increase in Temp. increasing in Pres.
1. towards product towards product
2. towards reactant towards product
3. towards reactant. towards reactant
4. towards product. towards reactant
solution : above reaction is an exothermic reaction ( because heat is negative ) and in exothermic reaction, heat is essentially a product of the reaction.
according to Le Chatelier's principle , when we increase the temperature, we increase the product so the reaction goes backwards to balance it. i.e., reaction shifts towards reactant when the temperature is increased.
again, according to Le Chatelier's principle, when we increase the pressure on a gas reaction, it shifts the position of equilibrium towards the side with fewer molecules.
now see reaction where you see fewer molecules, of course right side (product) so the reaction shifts towards the product when the pressure is increased.
Therefore the correct option is (2)