JEE Main levelNumerical answerDifficulty 2 of 3sc079
A reaction has Ea=100kJmol−1 without a catalyst and 75kJmol−1 with a catalyst, with the same pre-exponential factor. At 300K, calculate log10(kcat/kuncat) to two decimals. Use R=8.314Jmol−1K−1 and 2.303 for ln10.
Numerical answer type, tolerance 0.01.
Answer: 4.35
From k=Ae−Ea/RT with equal A, log10(kcat/kuncat)=ΔEa/(2.303RT). This is 25000/(2.303×8.314×300)=4.352, i.e. 4.35.