Assertion (A): Enthalpy of graphite is lower than that of diamond.
Reason (R ) : Entropy of graphite is lower than that of diamond.

(A): Enthalpy of graphite is lower than that of diamond. (R): Entropy of graphite is greater than that of diamond.

Assertion: Standard enthalpy of graphite is lower than that of diamond. Reason : Standard enthalpy of elements is taken to be zero arbitrarily.

Graphite is denser than diamond.

Graphite is denser than diamond

is Graphite isostructural with diamond?

The value of DeltaH_("transition") of C (graphite) rarr C (diamond) is 1.9 kJ/mol at 25^(@)C . Entropy of graphite is higher than entropy of diamond. This implies that :

The value of DeltaH_("transition") of C (graphite) rarr C (diamond) is 1.9 kJ/mol at 25^(@)C . Entropy of graphite is higher than entropy of diamond. This implies that :

Assertion (A) : Graphite is chemically more reactive than diamond . Reason (R) : Diamond is very hard but fraphite si soof .