Chemical Kinetics

JEE Main 2025 (Online) 22nd January Morning ShiftMCQEasy📈 Topic in 24% papers+4−1

Ques. 1JEE Main 2025, 22 January (Morning Shift)

Which of the following statement is not true for radioactive decay?

Half life is 2 times of 1rate constant.
Decay constant increases with increase in temperature.
Decay constant does not depend upon temperature.
Amount of radioactive substance remained after three half lives is 18th of original amount.

Answer

(2) Decay constant increases with increase in temperature.

Radioactive decay is a nuclear first-order process: does not depend on temperature.

(1) t1/2 = 2 1 , (3) and (4) ( 12 )3 = 18 are true.

statement (2) is not true.

Answer: (2)

Out of syllabus

Ques. 2JEE Main 2025, 22 January (Evening Shift)

Consider the given figure and choose the correct option : [figure]

Activation energy of both forward and backward reaction is E1 + E2 and reactant is more stable than product.
Activation energy of forward reaction is E1 + E2 and product is more stable than reactant.
Activation energy of backward reaction is E1 and product is more stable than reactant.
Activation energy of forward reaction is E1 + E2 and product is less stable than reactant.

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