Third Law of Thermodynamics

What is residual entropy of the substance?

Calculate the entropy change for the following reaction at $298 \mathrm{K}$ and $1 \mathrm{atm}$ pressure.

$2\mathrm{CO}\left(\mathrm{g}\right)+{\mathrm{O}}_2\left(\mathrm{g}\right)\stackrel{ }{\to }2{\mathrm{CO}}_2\left(\mathrm{g}\right)$, the absolute entropy values (${\mathrm{S}}^{\circ }$) for ${\mathrm{CO}}_2\left(\mathrm{g}\right)=213.6 \mathrm{J} \mathrm{K} {\mathrm{mol}}^{-1}, \mathrm{CO}\left(\mathrm{g}\right)=197.6 \mathrm{J} \mathrm{K} {\mathrm{mol}}^{-1}$ and ${\mathrm{O}}_2\left(\mathrm{g}\right)=205.0 \mathrm{J} \mathrm{K} {\mathrm{mol}}^{-1}$.

Write the statement of third law of thermodynamics.

Third law of thermodynamics helps in the calculation of the absolute entropy of a substance at any temperature ‘$\mathrm{T}$’.

The third law of thermodynamics states that, the entropy of a perfect crystal at a temperature of zero degree Celsius is equal to zero.

State the third law of thermodynamics.

Why is it impossible for any substance to have an absolute entropy zero at temperature greater than $0 \mathrm{K}$?

State third law of thermodynamics. What is its usefulness?

Entropy is a measure of disorder. For perfect crystalline substances at $0\mathrm{K}$, entropy becomes:

For a perfectly crystalline solid C_p,m = aT³ , where 'a' is constant. If C_p,m is $\text{0.42 }\frac{\text{J}}{\text{K mol}}$ at 10 K, molar entropy at 20 K is :

Which law of thermodynamics help in calculating entropy at different temperatures?

The entropy of a perfectly crystalline material is zero at $0 \mathrm{K}$. This statement matches with the-

The entropy of a perfectly crystalline material is zero at 0 K. This is statement of