Which of the following has the highest standard molar entropy (S°) at 298 K?
Practice Questions
Q1
Which of the following has the highest standard molar entropy (S°) at 298 K?
H2(g)
O2(g)
N2(g)
H2O(l)
Questions & Step-by-Step Solutions
Which of the following has the highest standard molar entropy (S°) at 298 K?
Correct Answer: H2O(l)
Step 1: Understand what standard molar entropy (S°) means. It is a measure of the amount of disorder or randomness in a substance at a specific temperature (298 K).
Step 2: Compare the substances given in the question. Look for their states (solid, liquid, gas) and molecular complexity.
Step 3: Recognize that gases generally have higher entropy than liquids and solids because they have more freedom of movement.
Step 4: Note that H2O(l) is a liquid, and while it has some molecular complexity due to hydrogen bonding, it is still less disordered than gases.
Step 5: Compare H2O(l) with diatomic gases (like O2, N2, etc.). Diatomic gases have more ways to move and rotate, leading to higher entropy.
Step 6: Conclude that H2O(l) has a higher standard molar entropy than diatomic gases due to its molecular complexity and interactions.
