NEET · Chemistry · STD 11 - 5. Thermodynamics and thermochemistry

The heat of combustion of carbon to \(CO_2\) is \( -393.5\ kJ/mol.\) The heat released upon formation of \(35.2\ g\) of \(CO_2\) from carbon and oxygen gas is

A \(+ 315\, kJ\)
B \(- 630\, kJ\)
C \(- 3.15\,kJ\)
D None of the above

Verified Solution

Answer & Solution

Correct Answer

(D) None of the above

Step-by-step Solution

Detailed explanation

Formation of \(\mathrm{CO}_{2}\) from carbon and dioxygen gas can be represented as: \(\mathrm{C}_{\mathrm{(s)}}+\mathrm{O}_{2(\mathrm{g})} \longrightarrow \mathrm{CO}_{2(\mathrm{g})} \quad \Delta_{f} H=-393.5 \;\mathrm{kJ}\, \mathrm{mol}^{-1}\)

Apply the relevant identity from the chapter and substitute the values established in the previous step, keeping the original constraint in view.

Use the simplified expression to isolate the unknown, then plug the result back into the question setup to confirm the working is internally consistent.

Cross-check against a boundary or limiting case. Both the dimensional balance and the qualitative behaviour at the extreme should agree with the candidate answer.

Combine the steps above to identify the correct option. The remaining choices each fail at least one of the consistency, dimensional, or boundary checks.

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Match column \(I\) with column \(II\) and select the correct option using the codes given below.

Column \(-I\)	Column \(-II\)
\((A)\) Citric acid	\((i)\) Trichoderma
\((B)\) Cyclosporin \(A\)	\((ii)\) Clostridium
\((C)\) Statins	\((iii)\) Aspergillus
\((D)\) Butyric acid	\((iv)\) Monascus

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