Students investigate the rate of reaction between magnesium ribbon and dilute hydrochloric acid at different temperatures. They measure the time taken for a 2.0 cm2.0 \text{ cm}2.0 cm length of magnesium ribbon to completely react and disappear.
Their results are shown in the table below:
| Temperature (∘C^{\circ}\text{C}∘C) | Reaction time (s\text{s}s) | Rate of reaction (s−1\text{s}^{-1}s−1) |
|---|---|---|
| 20 | 160 | 6.3×10−36.3 \times 10^{-3}6.3×10−3 |
| 30 | 80 | 1.3×10−21.3 \times 10^{-2}1.3×10−2 |
| 40 | 45 | 2.2×10−22.2 \times 10^{-2}2.2×10−2 |
| 50 | 28 | 3.6×10−23.6 \times 10^{-2}3.6×10−2 |
| 60 | 18 | 5.6×10−25.6 \times 10^{-2}5.6×10−2 |
Describe the relationship between temperature and the rate of reaction.
Explain your answer to part (a) using collision theory. Include ideas about particle energy, collision frequency, and successful collisions.
In another trial at 70∘C70^{\circ}\text{C}70∘C, the reaction time was found to be 11 s11 \text{ s}11 s. Calculate the rate of reaction at this temperature. Give your answer in scientific notation to two significant figures.