MHTCET 14 May 2023 Shift 1 Solved Paper

In the case of a first-order reaction, the half-life (which is the time taken for half of the reactant to be used up in the reaction) can be calculated using the following formula:
t1∕2=‌

0.693

k

where t1∕2 is the half-life and k is the rate constant of the reaction.
Given that the rate constant k=2.772×10−3 s−1, we can plug this into our formula to find the half-life:
t1∕2=‌

0.693

2.772×10−3 s−1

To calculate this, first divide 0.693 by 2.772×10−3 :
‌t1∕2=‌

0.693

2.772×10−3

‌t1∕2=250 s
Therefore, the half-life of the reaction is 250 seconds. The correct option is:
Option B : 250 s