Magnesium ribbon reacts with dilute hydrochloric acid to produce magnesium chloride and hydrogen gas.
An experiment was set up to investigate the rate of this reaction. Magnesium ribbon was added to a conical flask containing excess hydrochloric acid, and the hydrogen gas evolved was collected using a gas syringe.
The graph below shows the volume of hydrogen gas collected over the course of the reaction at two different temperatures, 25 ∘C25\ ^\circ\text{C}25 ∘C and 45 ∘C45\ ^\circ\text{C}45 ∘C.
Complete the graph by providing the missing label for the horizontal axis.
