Question

Which of the following is an example of a redox reaction?

• A. \( \text{H}_2 + \text{Cl}_2 \rightarrow 2 \text{HCl} \)
• B. \( \text{NaCl} + \text{AgNO}_3 \rightarrow \text{NaNO}_3 + \text{AgCl} \)
• C. \( \text{C}_2 \text{H}_5 \text{OH} + \text{O}_2 \rightarrow 2 \text{H}_2 \text{O} \)
• D. \( \text{H}_2 + \text{O}_2 \rightarrow 2 \text{H}_2 \text{O} \)

Hint:

Remember: Redox reactions involve the transfer of electrons. Identify oxidation and reduction to classify redox reactions.

Answer 1

The Correct Option is A

Step 1: Understand Redox Reactions A redox reaction is a type of chemical reaction in which the oxidation states of atoms are changed. Oxidation involves the loss of electrons, and reduction involves the gain of electrons. Step 2: Identify the Redox Reaction - In option (1), \( \text{H}_2 + \text{Cl}_2 \rightarrow 2 \text{HCl} \), hydrogen (\( \text{H}_2 \)) is oxidized, and chlorine (\( \text{Cl}_2 \)) is reduced. This is a redox reaction. - In option (2), \( \text{NaCl} + \text{AgNO}_3 \rightarrow \text{NaNO}_3 + \text{AgCl} \), there is no change in oxidation states; this is a double displacement reaction, not a redox reaction. - In option (3), \( \text{C}_2 \text{H}_5 \text{OH} + \text{O}_2 \rightarrow 2 \text{H}_2 \text{O} \), there is no clear change in oxidation states. - In option (4), \( \text{H}_2 + \text{O}_2 \rightarrow 2 \text{H}_2 \text{O} \), oxygen is reduced, but hydrogen is not oxidized. Answer: The correct answer is option (1): \( \text{H}_2 + \text{Cl}_2 \rightarrow 2 \text{HCl} \).