1
JEE Main 2021 (Online) 31st August Evening Shift
Numerical
+4
-1
For the reaction A $$\to$$ B, the rate constant k(in s$$-$$1) is given by

$${\log _{10}}k = 20.35 - {{(2.47 \times {{10}^3})} \over T}$$

The energy of activation in kJ mol$$-$$1 is ____________. (Nearest integer) [Given : R = 8.314 J K$$-$$1 mol$$-$$1]
2
JEE Main 2021 (Online) 31st August Morning Shift
Numerical
+4
-1
For a first order reaction, the ratio of the time for 75% completion of a reaction to the time for 50% completion is ____________. (Integer answer)
3
JEE Main 2021 (Online) 31st August Morning Shift
Numerical
+4
-1
According to the following figure, the magnitude of the enthalpy change of the reaction

A + B $$\to$$ M + N in kJ mol$$-$$ is equal to ___________. (Integer answer)

4
JEE Main 2021 (Online) 27th August Evening Shift
Numerical
+4
-1
The first order rate constant for the decomposition of CaCO3 at 700 K is 6.36 $$\times$$ 10$$-$$3s$$-$$1 and activation energy is 209 kJ mol$$-$$1. Its rate constant (in s$$-$$1) at 600 K is x $$\times$$ 10$$-$$6. The value of x is ___________. (Nearest integer)

[Given R = 8.31 J K$$-$$ mol$$-$$1; log 6.36 $$\times$$ 10$$-$$3 = $$-$$2.19, 10$$-$$4.79 = 1.62 $$\times$$ 10$$-$$5]