In the redox reaction 2PbO + C → 2Pb + CO2, which of the given statements about oxidation and reduction are incorrect?

Introduction / Context:
This question checks understanding of oxidation and reduction in a typical metal oxide reduction reaction. The example is the reduction of lead oxide with carbon, a common illustration of how metal oxides can be reduced to metals using a reducing agent. Correctly identifying which species are oxidised and reduced is central to mastering redox chemistry, which appears in metal extraction, corrosion, batteries, and many other chemical processes.

Given Data / Assumptions:

• Consider the balanced reaction: 2PbO + C → 2Pb + CO2.
• Statement A: Carbon dioxide is getting oxidised.
• Statement B: Lead is getting reduced.
• Statement C: Carbon is oxidised.
• Statement D: Lead oxide is getting reduced.
• The task is to find which statements are incorrect.

Concept / Approach:
Oxidation and reduction can be understood in terms of oxygen gain and loss or in terms of changes in oxidation number. In metal oxide reductions:

• The metal oxide usually loses oxygen and is reduced to the metal.
• The reducing agent, often carbon, gains oxygen and is oxidised to carbon dioxide or carbon monoxide.

We assign oxidation numbers to carbon, lead, and oxygen on both sides, then check each statement against these changes to decide whether it is correct or incorrect.

Step-by-Step Solution:
Step 1: Assign oxidation numbers in 2PbO + C. In PbO: oxygen has oxidation number -2, so lead must be +2 to make the compound neutral. In elemental carbon C: oxidation number is 0. Step 2: Assign oxidation numbers in 2Pb + CO2. In elemental lead Pb: oxidation number is 0. In CO2: oxygen is -2 each, total -4, so carbon must be +4. Step 3: Identify oxidation and reduction. Lead goes from +2 in PbO to 0 in Pb, so lead has been reduced. Carbon goes from 0 in C to +4 in CO2, so carbon has been oxidised. Lead oxide, the compound containing Pb2+, loses oxygen and is reduced to lead metal. Carbon dioxide is a product and does not undergo further change in this reaction, so it is not oxidised here.

Verification / Alternative Check:
Using the oxygen gain or loss idea, we see that the oxide PbO loses oxygen to form Pb, which is reduction. The element carbon gains oxygen to form CO2, so it is oxidised. Carbon dioxide already contains oxygen and is not gaining still more oxygen in this reaction, so it cannot be described as getting oxidised. This alternative view confirms the result obtained from oxidation numbers and supports our classification of the statements.

Why Other Options Are Wrong:
Statement A: It claims that carbon dioxide is getting oxidised. In fact, CO2 is a final product and does not further gain oxygen in this reaction, so this statement is incorrect. Statement B: It says lead is getting reduced. Lead metal is the product that results from reduction of lead oxide. However the wording is ambiguous because the species that is reduced is really lead oxide. As per standard teaching, we say PbO is reduced to Pb, not that Pb itself is reduced, so this statement is treated as incorrect. Statement C: It states that carbon is oxidised. This is correct because carbon goes from oxidation number 0 to +4 in CO2. Statement D: It says lead oxide is reduced. This is correct because PbO loses oxygen to form Pb metal. Because A and B are the only incorrect statements, the option that lists A and B together is correct.

Common Pitfalls:
Learners often confuse the species that is reduced with the metal produced and may say that lead is reduced rather than lead oxide. Another common misunderstanding is to think that any compound containing oxygen is always oxidised further in every reaction, which leads to the mistake about carbon dioxide. Careful use of oxidation numbers and checking which substance gains or loses oxygen helps avoid these errors.

Final Answer:
The incorrect statements are A and B, so the correct choice is A and B.