Question

ln the reaction; $A+2B\to 3C+D$, which of the following expressions does not describe changes in the concentration of various species as a function of time

• A. $\frac{d\left[C\right]}{dt}$ = $\frac{–3d\left[A\right]}{dt}$
  
• B. $\frac{3d\left[D\right]}{dt}$ = $\frac{d\left[C\right]}{dt}$
  
• C. $\frac{3d\left[B\right]}{dt}$ = $\frac{-2d\left[C\right]}{dt}$
  
• D. $\frac{2d\left[B\right]}{dt}$ = $\frac{d\left[A\right]}{dt}$

Answer 1

The correct option is D $\frac{2d\left[B\right]}{dt}$ = $\frac{d\left[A\right]}{dt}$

$A+2B\to 3C+D$
The rates of formation of C and D and rates of disappearances of A and B can be related as

$\frac{-d\left[A\right]}{dt}$ = $\frac{1}{2}\frac{-d\left[B\right]}{dt}$=$\frac{1}{3}\frac{d\left[C\right]}{dt}$ = $\frac{d\left[D\right]}{dt}$

So only option D is wrong