Step 1: Effect of Temperature:
- Higher temperature increases reaction rate by providing activation energy.
- Follows Arrhenius equation:
\[
k = A e^{-E_a/RT}
\]
Step 2: First-Order Reaction Calculation:
Given: 20\% completion in 10 minutes.
\[
k = \frac{2.303}{t} \log \frac{[A]_0}{[A]}
\]
\[
k = \frac{2.303}{10} \log \frac{100}{80}
\]
\[
k = \frac{2.303}{10} \times 0.0969 = 0.0223 \text{ min}^{-1}
\]
For 80\% completion:
\[
t = \frac{2.303}{k} \log \frac{100}{20}
\]
\[
t = \frac{2.303}{0.0223} \times 0.6989
\]
\[
t = 72.2 \text{ minutes}
\]
Thus, the time required for 80\% completion is 72.2 minutes.