---
title: "A student sets up an experiment using two rigid glass bulbs of equal volume connected by a valve, as represented in the particulate diagram. Initially, Bulb 1 contains a gas sample at a constant temperature of 298 K, and Bulb 2 is evacuated. After the valve is opened, the gas expands isothermally until it is evenly distributed across both bulbs. Which of the following best explains why \\(\\Delta S > 0\\) for this process based on the particulate representation?"
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url: "https://nerd-notes.com/ubq/119314/"
date_modified: "2026-08-19T12:39:46+00:00"
---

# A student sets up an experiment using two rigid glass bulbs of equal volume connected by a valve, as represented in the particulate diagram. Initially, Bulb 1 contains a gas sample at a constant temperature of 298 K, and Bulb 2 is evacuated. After the valve is opened, the gas expands isothermally until it is evenly distributed across both bulbs. Which of the following best explains why \(\Delta S > 0\) for this process based on the particulate representation?

A student sets up an experiment using two rigid glass bulbs of equal volume connected by a valve, as represented in the particulate diagram. Initially, Bulb 1 contains a gas sample at a constant temperature of 298 K, and Bulb 2 is evacuated. After the valve is opened, the gas expands isothermally until it is evenly distributed across both bulbs. Which of the following best explains why \(\Delta S > 0\) for this process based on the particulate representation?

![A schematic diagram showing two states labeled Initial State and Final State, separated by a rightward arrow. A legend at the top defines an open circle as a gas particle. In Initial State, two identical spherical glass bulbs connected horizontally by a closed valve are shown. The left bulb, labeled Bulb 1, contains exactly 4 open circles evenly distributed. The right bulb, labeled Bulb 2, contains 0 particles and is labeled Evacuated. In Final State, the valve between the two bulbs is open. Bulb 1 contains exactly 2 open circles, and Bulb 2 contains exactly 2 open circles. No other particles, labels, text, or annotations appear.](https://nerd-notes.com/wp-content/uploads/ubq-frq-generated/stem-fig-1-1787143186-HxBbAt.jpg)

- **A.** The gas particles occupy a larger total volume, which increases the number of possible spatial arrangements (microstates) available to the system.
- **B.** The average kinetic energy of the gas particles increases as they enter Bulb 2, leading to greater thermal disorder in the system.
- **C.** The total number of gas particles in the system increases when the valve is opened, creating a greater quantity of matter.
- **D.** The attractive forces between the gas particles become stronger as the gas expands, causing a spontaneous increase in energy.

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/119314/*