A student is investigating different experimental techniques to continuously monitor the rates of four different reactions.
Which of the following reactions is paired with an unsuitable continuous monitoring method?
CH3COCH3(aq)+I2(aq)→H+CH3COCH2I(aq)+H+(aq)+I−(aq)\text{CH}_3\text{COCH}_3(\text{aq}) + \text{I}_2(\text{aq}) \xrightarrow{\text{H}^+} \text{CH}_3\text{COCH}_2\text{I}(\text{aq}) + \text{H}^+(\text{aq}) + \text{I}^-(\text{aq})CH3COCH3(aq)+I2(aq)H+CH3COCH2I(aq)+H+(aq)+I−(aq) monitored using colorimetry
CH3CH2Br(l)+OH−(aq)→CH3CH2OH(aq)+Br−(aq)\text{CH}_3\text{CH}_2\text{Br}(\text{l}) + \text{OH}^-(\text{aq}) \rightarrow \text{CH}_3\text{CH}_2\text{OH}(\text{aq}) + \text{Br}^-(\text{aq})CH3CH2Br(l)+OH−(aq)→CH3CH2OH(aq)+Br−(aq) monitored using a pH probe
Zn(s)+H2SO4(aq)→ZnSO4(aq)+H2(g)\text{Zn}(\text{s}) + \text{H}_2\text{SO}_4(\text{aq}) \rightarrow \text{ZnSO}_4(\text{aq}) + \text{H}_2(\text{g})Zn(s)+H2SO4(aq)→ZnSO4(aq)+H2(g) monitored using Method 1 (Mass Loss)
CH3CH2Cl(l)+H2O(l)→CH3CH2OH(aq)+H+(aq)+Cl−(aq)\text{CH}_3\text{CH}_2\text{Cl}(\text{l}) + \text{H}_2\text{O}(\text{l}) \rightarrow \text{CH}_3\text{CH}_2\text{OH}(\text{aq}) + \text{H}^+(\text{aq}) + \text{Cl}^-(\text{aq})CH3CH2Cl(l)+H2O(l)→CH3CH2OH(aq)+H+(aq)+Cl−(aq) monitored using electrical conductivity