Assertion: Enthalpy of graphite is lower than that of diamond. Reason: Entropy of graphite is greater than that of diamond.

Question

Assertion: Enthalpy of graphite is lower than that of diamond. Reason: Entropy of graphite is greater than that of diamond. (A) If both Assertion and Reason are true and the Reason is a correct explanation of the Assertion (B) If both Assertion and Reason are true but Reason is not a correct explanation of the Assertion (C) If Assertion is true but the Reason is false (D) If both Assertion and Reason are false

Tardigrade Admin · Accepted Answer

Greater entropy of graphite is related to its structure as graphite is less compact and rigid than diamond. Δ H°f for graphite is zero, but the Δ H°f for diamond is 2 kJ/mol. That is because graphite is the standard state for carbon, not diamond.

Q. Assertion: Enthalpy of graphite is lower than that of diamond.
Reason: Entropy of graphite is greater than that of diamond.

If both Assertion and Reason are true and the Reason is a correct explanation of the Assertion

If both Assertion and Reason are true but Reason is not a correct explanation of the Assertion

If Assertion is true but the Reason is false

If both Assertion and Reason are false

Greater entropy of graphite is related to its structure as graphite is less compact and rigid than diamond. $Δ H_{f}^{\circ}$ for graphite is zero, but the $Δ H_{f}^{\circ}$ for diamond is $2 k J / m o l$ . That is because graphite is the standard state for carbon, not diamond.

Q. Assertion: Enthalpy of graphite is lower than that of diamond. Reason: Entropy of graphite is greater than that of diamond.