Question

The oxidation of certain metals is found to obey the equation ${\tau }^2=\alpha t+\beta$, where $\tau$ is the thickness of the oxide film at time t, $\alpha$ and $\beta$ are constants. What is the order of this reaction?

• A. pseudo 1st order
• B. 0
• C. 1
• D. -1

Answer 1

The correct option is D -1

The order of this reaction is -1.

${\tau }^2=\alpha t+\beta$

Rate $=\frac{d\tau }{dt}=\frac{\alpha }{2\tau }$

Hence, rate is inversely proportional to $\tau$

So, order $=-1$