The apparatus is used to monitor the rate of reaction between magnesium carbonate, $\text{MgCO}_3$, and dilute nitric acid, $\text{HNO}_3$. $\text{MgCO}_3(s) + 2\text{HNO}_3(aq) \rightarrow \text{Mg(NO}_3)_2(aq) + \text{H}_2\text{O}(l) + \text{CO}_2(g)$ The graph plots the volume of gas collected against time. Three claims are given about the experiment. 1. The mass of the flask and its contents falls as time passes. 2. The reaction rate falls as time passes. 3. The reaction has ended after four minutes. Which statements are correct?
- A1, 2 and 3
- B1 and 2 only
- C1 and 3 only
- D2 and 3 only