Question

For a chemical reaction, half-life period ($t_{1/2}$) is 10 minutes. How much reactant will be left after 20 minutes if one starts with 100 moles of reactant and the order of the reaction be (i) zero, (ii) one and (iii) two?

• A. 0, 25, 33.33
• B. 25, 0, 33.33
• C. 33.33, 25, 0
• D. 25, 33.33, 0

Hint:

Half-life memory trick: \begin{itemize} \item First order: constant halving \item Zero order: linear decay \item Second order: concentration decreases slowly \end{itemize} More order $\Rightarrow$ slower depletion at long times.

Answer 1

The Correct Option is D