Question

The standard absolute entropy of a substance , \[\left( {{S^\theta }} \right)\] is the entropy of the substance in its standard state at 1atm, temperature being:

Answer 1

Hint: For this question consider the third law of thermodynamics and solve using normal room temperature which is \[{25^\circ }C\].
Step by step solution:
We know that the standard units are in room temperature
\[T = {25^\circ }C = 298K\]
Only at absolute zero does a substance's constituent particles have a perfectly ordered structure. As a result, only at absolute zero is entropy zero. The heat shift involved in forming one mole of a material from its constituent elements is called enthalpy of formation. There is no heat shift when an element is created from itself, i.e. \[{\Delta _f}{H^\circ } = 0\].
On the other hand, the sum of energy that is inaccessible to do work is measured by an object's entropy. Entropy is also a metric for the number of possible configurations for atoms in a system. Entropy is a measure of uncertainty or unpredictability in this sense.
The entropy of a perfect crystal at zero Kelvin (absolute zero) is equal to zero, according to the third law of thermodynamics.
The entropy of a material at 1atm pressure is its normal entropy and 298K, and expressed in \[J{K^1}mo{l^1}\] units.

Note:
Thermodynamics arose from a desire to improve the efficiency of early steam engines, especially through the work of French physicist Nicolas Léonard Sadi Carnot (1824), who claimed that increasing engine efficiency would help France win the Napoleonic Wars. 1st In 1854, Lord Kelvin, a Scots-Irish physicist, was the first to formulate a succinct description of thermodynamics.