A student investigated the rate of reaction between calcium carbonate and hydrochloric acid by measuring the loss in mass. The results for two different acid concentrations are shown below as Curve X and Curve Y.
| Time / s | Loss in mass / g (Curve X) | Loss in mass / g (Curve Y) |
|---|---|---|
| 0 | 0.00 | 0.00 |
| 20 | 0.35 | 0.15 |
| 40 | 0.58 | 0.28 |
| 60 | 0.72 | 0.40 |
| 80 | 0.80 | 0.50 |
| 100 | 0.83 | 0.58 |
| 120 | 0.85 | 0.64 |
| 140 | 0.85 | 0.69 |
| 160 | 0.85 | 0.73 |
| 180 | 0.85 | 0.75 |
Calculate the rate of reaction on Curve X at 30 seconds by using the tangent drawn.
