Question

Which statement is correct regarding the reaction below? 3A + 2B yields C + 2D The rate of formation of D is twice the rate of disappearance of A. The rate of disappearance of A is one-third the rate of formation of C. The rate of formation of C is twice the rate of appearance of D. The rate of disappearance of B is twice the rate of appearance of C.

Answer 1

Answer:

The correct statements are:

The rate of disappearance of B is twice the rate of appearance of C.

Explanation:

Rate of the reaction is a change in the concentration of any one of the reactant or product per unit time.

3A + 2B → C + 2D

Rate of the reaction:

$R=-\frac{1}{3}\times \frac{d[A]}{dt}=-\frac{1}{2}\times \frac{d[B]}{dt}$

$-\frac{1}{3}\times \frac{d[A]}{dt}=\frac{1}{1}\times \frac{d[C]}{dt}$

$-\frac{1}{3}\times \frac{d[A]}{dt}=\frac{1}{2}\times \frac{d[D]}{dt}$

The rate of disappearance of B is twice the rate of appearance of C.

$\frac{1}{1}\times \frac{d[C]}{dt}=-\frac{1}{2}\times \frac{d[B]}{dt}$

$2\times \frac{1}{1}\times \frac{d[C]}{dt}=-\frac{1}{1}\times \frac{d[B]}{dt}$

Answer 2

Answer: D. The rate of disappearance of B is twice the rate of appearance of C.

Explanation:-

Rate law says that rate of a reaction is directly proportional to the concentration of the reactants each raised to a stoichiometric coefficient determined experimentally called as order.

$3A+2B\rightarrow C+2D$

The rate in terms of reactants is given as negative as the concentration of reactants is decreasing with time whereas the rate in terms of products is given as positive as the concentration of products is increasing with time.

Rate in terms of disappearance of A = $-\frac{1d[A]}{3dt}$

Rate in terms of disappearance of B = $-\frac{1d[B]}{2dt}$

Rate in terms of appearance of C = $\frac{1d[C]}{dt}$

Rate in terms of appearance of D = $\frac{1d[D]}{2dt}$

1. The rate of formation of D is 2 by 3 times the rate of disappearance of A.

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

2. The rate of disappearance of A is three times the rate of formation of C.

$-\frac{1d[A]}{dt}=\frac{3d[C]}{dt}$

3. The rate of formation of C is half the rate of appearance of D.

$\frac{1d[C]}{dt}=\frac{1d[D]}{2dt}$

4. The rate of disappearance of B is twice the rate of appearance of C.

$-\frac{1d[B]}{dt}=\frac{2d[C]}{dt}$