An investigation was carried out into the rate of reaction of zinc metal with dilute hydrochloric acid.
In the first set of experiments, 2.0 g of large zinc granules were reacted with 40 cm3 of 0.40 mol dm-3 hydrochloric acid. This was repeated using 2.0 g of the same large granules with 40 cm3 of 0.80 mol dm-3 hydrochloric acid.
In the second set of experiments, the procedures were repeated using 2.0 g of fine zinc powder instead of the large granules.
In each experiment, the volume of hydrogen gas collected in 3 minutes was recorded. The results are shown in the table below.
| Concentration of hydrochloric acid (mol dm−3\text{mol dm}^{-3}mol dm−3) | Volume of gas collected from large zinc granules (cm3\text{cm}^3cm3) | Volume of gas collected from fine zinc powder (cm3\text{cm}^3cm3) |
|---|---|---|
| 0.40 | 8.5 | 24.2 |
| 0.80 | 16.8 | 48.5 |
Explain, in terms of particle collision theory, how these results show the effect of the surface area (particle size) of the zinc and the effect of the concentration of the acid on the rate of this reaction.
