NEETChemistryChemical Kinetics
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): For a first-order reaction, the plot of [R] versus time is a straight line with a y-intercept equal to [R]₀ . Reason (R): The integrated rate equation for a first-order reaction is [R] = -kt + [R]₀ , where [R]₀ is the initial concentration. In the light of the above statements, choose the most appr
Options
- ABoth Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A)
- BBoth Assertion (A) and Reason (R) are true but Reason (R) is not the correct explanation of Assertion (A)
- CAssertion (A) is true but Reason (R) is false
- DAssertion (A) is false but Reason (R) is true
Correct answer
A. Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A)
Step-by-step solution
The integrated rate equation for a first-order reaction is [R] = -kt + [R]₀ . This equation is of the form y = mx + c , which represents a straight line. Here, y = [R] , x = t , slope m = -k , and the y-intercept c = [R]₀ . Thus, the plot of [R] versus time is a straight line that intersects the y-axis at [R]₀ . Therefore, both Assertion (A) and Reason (R) are true, and Reason (R) provides the mathematical basis that correctly explains Assertion (A). Answer: Both Assertion (A) and Reason (R) are true and Reason (R)