The silver oxide-zinc battery is rechargeable and utilises sodium hydroxide, NaOH, solution as the electrolyte - VCE - SSCE Chemistry - Question 16 - 2018 - Paper 1
Question 16
The silver oxide-zinc battery is rechargeable and utilises sodium hydroxide, NaOH, solution as the electrolyte. The battery is used as a backup in spacecraft, if the... show full transcript
Worked Solution & Example Answer:The silver oxide-zinc battery is rechargeable and utilises sodium hydroxide, NaOH, solution as the electrolyte - VCE - SSCE Chemistry - Question 16 - 2018 - Paper 1
Step 1
A. $2Ag + 2OH^- \rightarrow Ag_2O + H_2O + 2e^-$
96%
114 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
This equation shows that silver ions from the silver oxide are reduced by hydroxide ions, producing silver oxide while releasing water and electrons. This is consistent with the recharging process.
Step 2
B. $Zn + H_2O + 2e^- \rightarrow Zn + 2OH^-$
99%
104 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
This equation suggests that zinc remains in its elemental state, which doesn't align with the recharging chemistry as zinc typically oxidizes.
Step 3
C. $ZnO + 2OH^- + 2e^- \rightarrow Zn + 2H_2O$
96%
101 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
In this case, zinc oxide is being reduced back to zinc, but the electrons appear to support reduction which is not the direct process happening at the anode.
Step 4
D. $Zn + 2OH^- \rightarrow ZnO + H_2 + 2e^-$
98%
120 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
This describes the oxidation of zinc to zinc oxide, but it includes hydrogen evolution at the anode, which is not the charging process.
