Question

Which of the following is not a valid way to describe the rate of the following reaction?
$A+B+C\to D+E$

• A. $\frac{-△\left[A\right]}{△t}$
• B. $\frac{-△\left[B\right]}{△t}$
• C. $\frac{-△\left[C\right]}{△t}$
• D. $\frac{-△\left[D\right]}{△t}$
• E. $\frac{-△\left[E\right]}{△t}$

Answer 1

Answer: (D), (E)

$\frac{-△\left[E\right]}{△t}$
$\frac{-△\left[D\right]}{△t}$

$A+B+C⟶D+E$

Rate of reaction is defined as the change in concentration of reactant or product to time.

Rate $\left(R\right)=\frac{-d\left[A\right]}{dt}=\frac{-d\left[B\right]}{dt}=\frac{-d\left[C\right]}{dt}=\frac{d\left[D\right]}{dt}=\frac{d\left[E\right]}{dt}$

Therefore, (D) & (E) i.e. $\frac{-d\left[D\right]}{dt}\&\frac{-d\left[E\right]}{dt}$ respectively are not valid ways of describing the rate of the following reaction.