Assertion(A) : Standard entropy of `O_(2)` gas is `gt 0`.
Reason(R ) : Entropy of free elements at the standard state conditions is equal to zero.

Which of the following element standard enthalpy is not to be equal to zero?

The quantity which is not zero for an element in its standard state at 298 K is

Assertion (A). Combustion of all organic compounds is an exothermic reaction. Reason (R). The enthalpies of all elements in their standard state are zero

Assertion (A). Combustion of all organic compounds is an exothermic reaction. Reason (R). The enthalpies of all elements in their standard state are zero

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

Statement-1 : Entropy of all elements is zero at zero Kelvin. Statement-2 : Standard entropy of all elements is greater than zero. Statement-3 : Entropy of all elements and compounds decreases with decrease of temperature and becomes zero at absolute zero temperature.

Statement-1 : Entropy of all elements is zero at zero Kelvin. Statement-2 : Standard entropy of all elements is greater than zero. Statement-3 : Entropy of all elements and compounds decreases with decrease of temperature and becomes zero at absolute zero temperature.

Enthalpy, entropy and free energy of formation of elementary substances in the standard state are taken as zero.