Question

In the reaction, $A+2 B \to C+2D, $ the initial rate $-d\left[A\right]/ dt at t=0$ was found to be $2.6\times10^{-2} M s^{-1}.$ What is the value of $-d \left[B\right] / dt \,at\, t=0 in \, Ms^{-1}?$

• A. $2.6\times10^{-2}$
• B. $5.2\times10^{-2}$
• C. $1.0\times10^{-1}$
• D. $6.5\times10^{-3}$

Answer 1

Answer: (B)

$\frac{d\left[A\right]}{d t}=-\frac{1}{2} \frac{d\left[B\right]}{d t}$
$Therefore, \, -\frac{d\left[B\right]}{d t}=2\times\frac{-d\left[A\right]}{d t}$
$=2\times2.6\times10^{-2} M s^{-1}=5.2\times10^{-2} M s^{-1}$