Question

sort the following from lowest to highest absolute entropy at a given temperature h₂(g), o₂(g), h₂o(s), h₂o(l), h₂o(g)

Explanation:

Step1: Recall entropy principles

Entropy is a measure of disorder. Solids have the least - disordered state and gases have the most. Also, larger, more complex molecules generally have higher entropy than smaller, simpler ones among gases.

Step2: Analyze each substance

• $H_2O(s)$ is a solid, so it has the lowest entropy among these substances as the molecules are in a fixed, ordered position.
• $H_2O(l)$ is a liquid. Molecules in a liquid are more disordered than in a solid but less disordered than in a gas, so its entropy is higher than that of $H_2O(s)$.
• $H_2(g)$ and $O_2(g)$ are gases. Among them, $O_2$ has a larger molar - mass and more electrons than $H_2$. Generally, for gases, larger molecules have higher entropy. So, the entropy of $O_2(g)$ is higher than that of $H_2(g)$.
• $H_2O(g)$ is a gas and is a more complex molecule compared to $H_2$ and $O_2$ in terms of the number of atoms and the structure, so it has the highest entropy.

Step3: Order the substances

The order from lowest to highest absolute entropy is $H_2O(s)

Answer:

$H_2O(s), H_2O(l), H_2(g), O_2(g), H_2O(g)$