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Group 7(17), the halogens

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Question 17

Household bleach is manufactured by reacting chlorine gas with a cold, dilute aqueous solution of sodium hydroxide.

Which of the following correctly identifies both the simplified ionic equation for this reaction and the change in oxidation state of the chlorine species that undergoes oxidation?

Ionic equation: Cl2(g)+2OH−(aq)→Cl−(aq)+ClO−(aq)+H2O(l)\text{Cl}_2(\text{g}) + 2\text{OH}^-(\text{aq}) \rightarrow \text{Cl}^-(\text{aq}) + \text{ClO}^-(\text{aq}) + \text{H}_2\text{O}(\text{l})Cl2​(g)+2OH−(aq)→Cl−(aq)+ClO−(aq)+H2​O(l)
Oxidation state change: 0→+10 \rightarrow +10→+1

Ionic equation: 3Cl2(g)+6OH−(aq)→5Cl−(aq)+ClO3−(aq)+3H2O(l)3\text{Cl}_2(\text{g}) + 6\text{OH}^-(\text{aq}) \rightarrow 5\text{Cl}^-(\text{aq}) + \text{ClO}_3^-(\text{aq}) + 3\text{H}_2\text{O}(\text{l})3Cl2​(g)+6OH−(aq)→5Cl−(aq)+ClO3−​(aq)+3H2​O(l)
Oxidation state change: 0→+50 \rightarrow +50→+5

Ionic equation: Cl2(g)+2OH−(aq)→Cl−(aq)+ClO−(aq)+H2O(l)\text{Cl}_2(\text{g}) + 2\text{OH}^-(\text{aq}) \rightarrow \text{Cl}^-(\text{aq}) + \text{ClO}^-(\text{aq}) + \text{H}_2\text{O}(\text{l})Cl2​(g)+2OH−(aq)→Cl−(aq)+ClO−(aq)+H2​O(l)
Oxidation state change: 0→−10 \rightarrow -10→−1

Ionic equation: 3Cl2(g)+6OH−(aq)→5Cl−(aq)+ClO3−(aq)+3H2O(l)3\text{Cl}_2(\text{g}) + 6\text{OH}^-(\text{aq}) \rightarrow 5\text{Cl}^-(\text{aq}) + \text{ClO}_3^-(\text{aq}) + 3\text{H}_2\text{O}(\text{l})3Cl2​(g)+6OH−(aq)→5Cl−(aq)+ClO3−​(aq)+3H2​O(l)
Oxidation state change: 0→+10 \rightarrow +10→+1

Group 7(17), the halogens Questions

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