---
title: "Two rigid glass bulbs, Bulb 1 of volume \\(V_0\\) and Bulb 2 of volume \\(2V_0\\), are connected by a narrow tube of negligible volume equipped with a closed stopcock. Bulb 1 is held at a constant absolute temperature \\(T_0\\) by a cold thermal bath, while Bulb 2 is held at a constant absolute temperature \\(2T_0\\) by a hot thermal bath. Initially, Bulb 1 contains an ideal gas at pressure \\(P_0\\) and Bulb 2 is completely evacuated. The stopcock is opened, allowing gas to flow between the bulbs until thermal and mechanical equilibrium is established while the baths maintain the temperatures of the respective bulbs. What is the final equilibrium pressure \\(P_f\\) of the gas system in terms of \\(P_0\\)?"
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url: "https://nerd-notes.com/ubq/116278/"
date_modified: "2026-08-03T11:46:43+00:00"
---

# Two rigid glass bulbs, Bulb 1 of volume \(V_0\) and Bulb 2 of volume \(2V_0\), are connected by a narrow tube of negligible volume equipped with a closed stopcock. Bulb 1 is held at a constant absolute temperature \(T_0\) by a cold thermal bath, while Bulb 2 is held at a constant absolute temperature \(2T_0\) by a hot thermal bath. Initially, Bulb 1 contains an ideal gas at pressure \(P_0\) and Bulb 2 is completely evacuated. The stopcock is opened, allowing gas to flow between the bulbs until thermal and mechanical equilibrium is established while the baths maintain the temperatures of the respective bulbs. What is the final equilibrium pressure \(P_f\) of the gas system in terms of \(P_0\)?

Two rigid glass bulbs, Bulb 1 of volume \(V_0\) and Bulb 2 of volume \(2V_0\), are connected by a narrow tube of negligible volume equipped with a closed stopcock. Bulb 1 is held at a constant absolute temperature \(T_0\) by a cold thermal bath, while Bulb 2 is held at a constant absolute temperature \(2T_0\) by a hot thermal bath. Initially, Bulb 1 contains an ideal gas at pressure \(P_0\) and Bulb 2 is completely evacuated. The stopcock is opened, allowing gas to flow between the bulbs until thermal and mechanical equilibrium is established while the baths maintain the temperatures of the respective bulbs. What is the final equilibrium pressure \(P_f\) of the gas system in terms of \(P_0\)?

![Two glass bulbs connected horizontally by a narrow tube with a central stopcock valve. The left bulb, labeled 'Bulb 1', has volume \(V_0\) and is submerged in a liquid bath labeled '\(T_1 = T_0\)'. The right bulb, labeled 'Bulb 2', is larger, with volume \(2V_0\), and is submerged in a liquid bath labeled '\(T_2 = 2T_0\)'. The stopcock valve in the middle tube is shown in the closed position. No other labels, lines, text, or axes appear.](https://nerd-notes.com/wp-content/uploads/ubq-frq-generated/stem-fig-1-1785757603-fjUE0X.jpg)

- **A.** \(\dfrac{1}{4} P_0\)
- **B.** \(\dfrac{1}{3} P_0\)
- **C.** \(\dfrac{2}{5} P_0\)
- **D.** \(\dfrac{1}{2} P_0\)

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/116278/*