The third law of thermodynamics states that:
AEntropy of a system cannot decrease
BThe total entropy of the universe is constant
CThe entropy of a perfectly crystalline substance at absolute zero is zero
DAbsolute zero of temperature can be reached in a finite number of steps
Answer & Solution
Correct answer: C. The entropy of a perfectly crystalline substance at absolute zero is zero
Third law: the entropy of a perfect crystalline substance at $T = 0\,\text{K}$ is taken to be zero. This provides an absolute reference for entropy, allowing tabulation of standard entropies $S^\circ$ at $298\,\text{K}$. Option D is the negation of an unattainability statement equivalent to the third law.
Related questions
A reaction has $\Delta H = -100$ kJ and $\Delta S = +200$ J/K. At $T = 298$ K, $\Delta G$ Among solid ice, liquid water, and water vapour at the same temperature, entropy is:Hess's law states that the standard enthalpy change for a reaction:For a reaction occurring at constant pressure in an open beaker, the heat absorbed equals:There are two spherical balls $A$ and $B$ of the same material with same surface, but the A cylindrical rod with one end in a steam chamber and the other end in ice results in meltAn ideal gas expands isothermally from a volume $V_{1}$ to $V_{2}$ and then compressed to Two cylinders $A$ and $B$ fitted with pistons contain equal amounts of an ideal diatomic g