Question

What is the value of the slope of a graph obtained by plotting the concentration of reactant \((A)_t\) versus time for zero order reaction?

• A. \(-k\)
• B. \(1/2k\)
• C. \(k/2.303\)
• D. \(2.303/k\)

Hint:

For zero order, [A] = [A]0 - kt, a straight line.

Answer 1

The Correct Option is A

Step 1: Differentiate:
Rate $= -\dfrac{d[A]}{dt} = k$ for zero order, since $[A]^0 = 1$.

Step 2: Read the slope:
So $\dfrac{d[A]}{dt} = -k$. This is a constant, which is the slope of the $[A]$ versus $t$ graph.

Step 3: Result:
The line goes down with slope $-k$. Option (A).

Final Answer:
The graph is a straight line falling with slope -k. \[ \boxed{A} \]