Question

If the rate of production of HCl is 3.0 X 10-5 M/s at a particular instant. What is the rate of consumption of SnCl4 at this same time?

Answer 1

Let's write the balanced reaction equation:

SnCl₄ + 4H₂O $\rightarrow$ Sn(OH)₄ + 4HCl

As you can see from this equation, when 1 mol of SnCl₄ reacts, 4 mol of HCl are produced. The rates of the reagents consumption and the rates of the products formation are related by stoichiometric coefficients. The rate of the reaction at a particular instant can be expressed as:

$r = -\frac{\text{d}[\text{SnCl}_4]}{\text{d}t} =\frac{1}{4}\cdot \frac{\text{d}[\text{HCl}]}{\text{d}t}$,

where $\frac{\text{d}[\text{SnCl}_4]}{\text{d}t}$  is the rate of consumption of SnCl₄ and $\frac{\text{d}[\text{HCl}]}{\text{d}t}$ is the rate of formation of HCl. The of consumption of SnCl₄ at the same time is:

$\frac{\text{d}[\text{SnCl}_4]}{\text{d}t} =- \frac{1}{4}\cdot 3.0 \cdot 10^{-5} =- 0.75\cdot 10^{-5}$ M/s

Answer: if the rate of production of HCl is 3.0 · 10^-5 M/s at a particular instant, the rate of consumption of SnCl₄ at this same time is -0.75 ·10^-5 M/s