Question
What is the standard cell potential of two half reactions which equal -0.40 V and +0.80 V
Answers
GPT-4o mini
To determine the standard cell potential of a galvanic cell comprised of two half-reactions, you can use the following formula:
\[
E_{\text{cell}} = E_{\text{cathode}} - E_{\text{anode}}
\]
Where:
- \( E_{\text{cathode}} \) is the standard reduction potential of the cathode half-reaction (which is the more positive value).
- \( E_{\text{anode}} \) is the standard reduction potential of the anode half-reaction (which is the less positive value or more negative).
In your case, you have one half-reaction with a potential of \(-0.40 \, \text{V}\) and another with \(+0.80 \, \text{V}\).
1. Identify the cathode and anode:
- Cathode (more positive): \( +0.80 \, \text{V} \)
- Anode (more negative): \(-0.40 \, \text{V}\)
2. Substitute the values into the formula:
\[
E_{\text{cell}} = (+0.80 \, \text{V}) - (-0.40 \, \text{V})
\]
\[
E_{\text{cell}} = +0.80 \, \text{V} + 0.40 \, \text{V} = +1.20 \, \text{V}
\]
So, the standard cell potential (\(E_{\text{cell}}\)) is \(+1.20 \, \text{V}\).
\[
E_{\text{cell}} = E_{\text{cathode}} - E_{\text{anode}}
\]
Where:
- \( E_{\text{cathode}} \) is the standard reduction potential of the cathode half-reaction (which is the more positive value).
- \( E_{\text{anode}} \) is the standard reduction potential of the anode half-reaction (which is the less positive value or more negative).
In your case, you have one half-reaction with a potential of \(-0.40 \, \text{V}\) and another with \(+0.80 \, \text{V}\).
1. Identify the cathode and anode:
- Cathode (more positive): \( +0.80 \, \text{V} \)
- Anode (more negative): \(-0.40 \, \text{V}\)
2. Substitute the values into the formula:
\[
E_{\text{cell}} = (+0.80 \, \text{V}) - (-0.40 \, \text{V})
\]
\[
E_{\text{cell}} = +0.80 \, \text{V} + 0.40 \, \text{V} = +1.20 \, \text{V}
\]
So, the standard cell potential (\(E_{\text{cell}}\)) is \(+1.20 \, \text{V}\).