In a galvanic cell, if the anode reaction is 2H₂ → 4H⁺ + 4e⁻, what is the cathode reaction?
Practice Questions
1 question
Q1
In a galvanic cell, if the anode reaction is 2H₂ → 4H⁺ + 4e⁻, what is the cathode reaction?
O₂ + 4e⁻ + 4H⁺ → 2H₂O
2H₂O + 4e⁻ → 2H₂ + O₂
4H⁺ + 4e⁻ → 2H₂
2H₂ + O₂ → 2H₂O
The cathode reaction is O₂ + 4e⁻ + 4H⁺ → 2H₂O.
Questions & Step-by-step Solutions
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Q
Q: In a galvanic cell, if the anode reaction is 2H₂ → 4H⁺ + 4e⁻, what is the cathode reaction?
Solution: The cathode reaction is O₂ + 4e⁻ + 4H⁺ → 2H₂O.
Steps: 7
Step 1: Understand that a galvanic cell has two electrodes: anode and cathode.
Step 2: The anode is where oxidation occurs. In this case, the reaction is 2H₂ → 4H⁺ + 4e⁻, meaning hydrogen gas is losing electrons.
Step 3: The cathode is where reduction occurs. This means it gains electrons.
Step 4: To find the cathode reaction, we need to know what species can accept the electrons produced at the anode.
Step 5: In a typical galvanic cell involving hydrogen, oxygen is often the species that accepts electrons.
Step 6: The reduction reaction at the cathode can be written as O₂ + 4e⁻ + 4H⁺ → 2H₂O, where oxygen gains electrons and combines with protons (H⁺) to form water.
Step 7: Therefore, the cathode reaction is O₂ + 4e⁻ + 4H⁺ → 2H₂O.
