Important Questions
1. Define ‘order of a reaction’.
2. Distinguish between ‘rate expression’ and ‘rate constant’ of a reaction.
3. Write two differences between ‘order of reaction’ and ‘molecularity of reaction’.
Sample Questions
1. What is meant by the ‘rate constant, k’ of a reaction? If the concentration be expressed in mol L–1 units and time in seconds, what would be the units for k
(i) for a zero order reaction and
(ii) for a first order reaction?
2. The rate of a reaction becomes four times when the temperature changes from 293 K to 313 K.
Calculate the energy of activation (Ea) of the reaction assuming that it does not change with temperature. [R = 8.314 J K–1 mole–1, log4 = 0.6021]
3. A first order reaction is 50% completed in 40 minutes at 300 K and in 20 minutes at 320K. Calculate the activation energy of the reaction.
(Given: log2 = 0.3010, log4 = 0.6021, R = 8.314 JK–1 mol–1)
