A student investigated the rate of reaction between magnesium ribbon and excess dilute hydrochloric acid:
Mg(s)+2HCl(aq)→MgCl2(aq)+H2(g) \text{Mg}(\text{s}) + 2\text{HCl}(\text{aq}) \rightarrow \text{MgCl}_2(\text{aq}) + \text{H}_2(\text{g}) Mg(s)+2HCl(aq)→MgCl2(aq)+H2(g)The volume of hydrogen gas produced was recorded over time. The results and a tangent drawn to the curve at t=30 st = 30\text{ s}t=30 s are shown below:
Using the tangent drawn on the graph, what is the rate of reaction at t=30 st = 30\text{ s}t=30 s?
1.20 cm3 s−11.20\text{ cm}^3\text{ s}^{-1}1.20 cm3 s−1
1.50 cm3 s−11.50\text{ cm}^3\text{ s}^{-1}1.50 cm3 s−1
1.92 cm3 s−11.92\text{ cm}^3\text{ s}^{-1}1.92 cm3 s−1
2.33 cm3 s−12.33\text{ cm}^3\text{ s}^{-1}2.33 cm3 s−1
