Consider the following statements Statement I: Studies indicate that carbon dioxide emissions from cement industry account for mo…

Question

Consider the following statements:

Statement I: Studies indicate that carbon dioxide emissions from cement industry account for more than 5% of global carbon emissions.

Statement II: Silica-bearing clay is mixed with limestone while manufacturing cement.

Statement III: Limestone is converted into lime during clinker production for cement manufacturing.

Which one of the following is correct in respect of the above statements?

1. A. Both Statement II and Statement III are correct and both of them explain Statement I
2. B. Both Statement II and Statement III are correct but only one of them explains Statement I (Correct answer)
3. C. Only one of the Statements II and III is correct and that explains Statement I
4. D. Neither Statement II nor Statement III is correct

Correct Answer

Option B — Both Statement II and Statement III are correct but only one of them explains Statement I

Detailed Solution & Explanation

The correct answer is Both Statement II and Statement III are correct but only one of them explains Statement I.

Key Points

• Cement accounts for approximately 8% of global CO2 emissions, well above 5% — Statement I is correct.
• Cement production involves mixing limestone with clay (silica-bearing) — Statement II is correct.
• During clinker production, limestone (CaCO3) is heated to produce lime (CaO) + CO2 — this calcination process is the primary source of cement CO2 emissions.
• Statement III is correct.
• However, only Statement III (calcination releasing CO2) directly explains Statement I; mixing clay (Statement II) does not cause CO2 emissions.
• Both II and III are correct, but only III explains I.