An excess of magnesium ribbon is placed into dilute hydrochloric acid, and the amount of hydrogen gas produced is measured while the reaction continues. The reaction gives out heat. The results are shown. Which row describes the changes in the rate of reaction from P to Q and from Q to R?
- Abetween P and Q: the reaction temperature is increasing; between Q and R: the acid concentration is falling
- Bbetween P and Q: the reaction temperature is increasing; between Q and R: the magnesium has been used up
- Cbetween P and Q: magnesium’s surface area is decreasing; between Q and R: the acid concentration is falling
- Dbetween P and Q: magnesium’s surface area is decreasing; between Q and R: the magnesium has been used up