Home
Class 12
CHEMISTRY
The potential associated with each elect...

The potential associated with each electrode is known as electrode potential. If the concentration of each species taking part in the electrode reaction is unity (if any appears in the electrode reaction, it is confined to 1 atmospheric pressure) and further the reaction is carried out at 298 K, then the potential of each electrode is said to the standard electrode potential. By convention, the standard electrode potential of hydrogen electrode is 0.0 volt. The electrode potential value for each electrode process is a measure of relative tendency of the active species in the process to remain in the oxidised/reduced form. A negative `E^(@)` means that the redox couple is a stronger reducing agent than the `H^(+)//H_(2)` couple. A positive `E^(@)` means that the redox couple is a weaker reducing agent than the `H^(+)//H_(2)` couple. The metal with greater positive value of standard reduction potential forms the oxide of greater thermal stability.
Which of the following reactions is not correct ?

A

`Zn+H_(2)SO_(4) to ZnSO_(4)+H_(2)`

B

`Fe+H_(2)SO_(4) to FeSO_(4)+H_(2)`

C

`Mg+H_(2)SO_(4) to MgSO_(4)+H_(2)`

D

`Cu+H_(2)SO_(4) to CuSO_(4)+H_(2)`

Text Solution

AI Generated Solution

The correct Answer is:
To determine which of the given reactions is not correct, we need to analyze the standard reduction potentials of the metals involved in each reaction and their ability to displace hydrogen from sulfuric acid (H₂SO₄). ### Step-by-Step Solution: 1. **Understand the Standard Reduction Potentials:** - The standard reduction potentials (E°) for the relevant half-reactions are: - \( \text{Zn}^{2+} + 2e^- \rightarrow \text{Zn} \) : \( E° = -0.78 \, \text{V} \) - \( \text{Fe}^{2+} + 2e^- \rightarrow \text{Fe} \) : \( E° = -0.44 \, \text{V} \) - \( \text{Mg}^{2+} + 2e^- \rightarrow \text{Mg} \) : \( E° = -2.37 \, \text{V} \) - \( \text{Cu}^{2+} + 2e^- \rightarrow \text{Cu} \) : \( E° = +0.337 \, \text{V} \) 2. **Identify the Reactions:** - The reactions given are: - (a) \( \text{Zn} + \text{H}_2\text{SO}_4 \rightarrow \text{ZnSO}_4 + \text{H}_2 \) - (b) \( \text{Fe} + \text{H}_2\text{SO}_4 \rightarrow \text{FeSO}_4 + \text{H}_2 \) - (c) \( \text{Mg} + \text{H}_2\text{SO}_4 \rightarrow \text{MgSO}_4 + \text{H}_2 \) - (d) \( \text{Cu} + \text{H}_2\text{SO}_4 \rightarrow \text{CuSO}_4 + \text{H}_2 \) 3. **Evaluate Each Reaction:** - **(a) Zn + H₂SO₄**: - Zn has a more negative E° than H⁺, so it can displace H₂. This reaction is correct. - **(b) Fe + H₂SO₄**: - Fe has a more negative E° than H⁺, so it can also displace H₂. This reaction is correct. - **(c) Mg + H₂SO₄**: - Mg has a much more negative E° than H⁺, so it can displace H₂. This reaction is correct. - **(d) Cu + H₂SO₄**: - Cu has a positive E° compared to H⁺, meaning it cannot displace H₂ from H₂SO₄. This reaction is not correct. 4. **Conclusion:** - The reaction that is not correct is **(d) Cu + H₂SO₄ → CuSO₄ + H₂**. ### Final Answer: The reaction that is not correct is **(d)**.
Promotional Banner

Similar Questions

Explore conceptually related problems

The potential associated with each electrode is known as electrode potential. If the concentration of each species taking part in the electrode reaction is unity (if any appears in the electrode reaction, it is confined to 1 atmospheric pressure) and further the reaction is carried out at 298 K, then the potential of each electrode is said to the standard electrode potential. By convention, the standard electrode potential of hydrogen electrode is 0.0 volt. The electrode potential value for each electrode process is a measure of relative tendency of the active species in the process to remain in the oxidised/reduced form. A negative E^(@) means that the redox couple is a stronger reducing agent than the H^(+)//H_(2) couple. A positive E^(@) means that the redox couple is a weaker reducing agent than the H^(+)//H_(2) couple. The metal with greater positive value of standard reduction potential forms the oxide of greater thermal stability. Which of the following couples will have highest value of emf ?

The potential associated. with each electrode is known as electrode potential. If the concentration of each species taking part in the electrode reaction is unity (if any gås appears in the electrode reaction, it is confined to 1 atmospheric pressure) and further the reaction is carried out at 298 K, then the potential of each electrode is said to be the standard electrode potential. By convention, the standard electrode potential of hydrogen electrode is 0:0 volt. The electrode potential value for each electrode process is a measure, of relative tendency of the active species in the process to remain in the oxidized / reduced form. A negative E^@ means that the redox couple is a stronger reducing agent than the H^(+)//H_2 couple. A positive E mears that the redox couple is a weaker reducing agent than. the H^(+)//H couple. The metal with greater positive value of standard reduction potentlal forms the oxide of greater thermal stability: Which of the following metals will not displace hydrogen from water?

The potential associated. with each electrode is known as electrode potential. If the concentration of each species taking part in the electrode reaction is unity (if any gås appears in the electrode reaction, it is confined to 1 atmospheric pressure) and further the reaction is carried out at 298 K, then the potential of each electrode is said to be the standard electrode potential. By convention, the standard electrode potential of hydrogen electrode is 0:0 volt. The electrode potential value for each electrode process is a measure, of relative tendency of the active species in the process to remain in the oxidized / reduced form. A negative E^@ means that the redox couple is a stronger reducing agent than the H^(+)//H_2 couple. A positive E mears that the redox couple is a weaker reducing agent than. the H^(+)//H couple. The metal with greater positive value of standard reduction potentlal forms the oxide of greater thermal stability: Which of the following oxides will be themally most stable?

The potential associated. with each electrode is known as electrode potential. If the concentration of each species taking part in the electrode reaction is unity (if any gås appears in the electrode reaction, it is confined to 1 atmospheric pressure) and further the reaction is carried out at 298 K, then the potential of each electrode is said to be the standard electrode potential. By convention, the standard electrode potential of hydrogen electrode is 0:0 volt. The electrode potential value for each electrode process is a measure, of relative tendency of the active species in the process to remain in the oxidized / reduced form. A negative E^@ means that the redox couple is a stronger reducing agent than the H^(+)//H_2 couple. A positive E mears that the redox couple is a weaker reducing agent than. the H^(+)//H couple. The metal with greater positive value of standard reduction potentlal forms the oxide of greater thermal stability: Given the standard reduction potentials. E_(K^(+)//K)^(@)=-2.93V, E_(Ag^(+)//Ag)^(@)=+0.80V, E_(Hg^(+)//Hg)^(@)=0.79V E_(Mg^(+)//Mg)^(@)=-2.37V, E_(Cr^(3+)//Cr)^(@)=-0.74V The correct increasing order of reducing power is:

Define standard electrode potential.

What is electrode potential?

What is electrode potential?

The electrode potential of hydrogen electrode at the pH=12 will be

Electrode potential depends upon

The potential of hydrogen electrode having a pH=10 is