A student wants to monitor the rate of a reaction by measuring the continuous loss in mass of the reaction mixture over time, using the experimental setup shown below:
For which of the following reactions is this method least suitable?
CaCO3(s)+2HCl(aq)→CaCl2(aq)+H2O(l)+CO2(g)
\text{CaCO}_3(\text{s}) + 2\text{HCl}(\text{aq}) \rightarrow \text{CaCl}_2(\text{aq}) + \text{H}_2\text{O}(\text{l}) + \text{CO}_2(\text{g})
CaCO3(s)+2HCl(aq)→CaCl2(aq)+H2O(l)+CO2(g)
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)
K2CO3(aq)+2HNO3(aq)→2KNO3(aq)+H2O(l)+CO2(g)
\text{K}_2\text{CO}_3(\text{aq}) + 2\text{HNO}_3(\text{aq}) \rightarrow 2\text{KNO}_3(\text{aq}) + \text{H}_2\text{O}(\text{l}) + \text{CO}_2(\text{g})
K2CO3(aq)+2HNO3(aq)→2KNO3(aq)+H2O(l)+CO2(g)
CuCO3(s)+H2SO4(aq)→CuSO4(aq)+H2O(l)+CO2(g)
\text{CuCO}_3(\text{s}) + \text{H}_2\text{SO}_4(\text{aq}) \rightarrow \text{CuSO}_4(\text{aq}) + \text{H}_2\text{O}(\text{l}) + \text{CO}_2(\text{g})
CuCO3(s)+H2SO4(aq)→CuSO4(aq)+H2O(l)+CO2(g)