---
title: "A student determines the molar mass of an unknown volatile liquid by vaporizing a sample in a container of fixed volume at a constant temperature and pressure. Under these conditions, the density of the unknown vapor is measured to be \\(3.60 \\text{ g/L}\\). Under the exact same temperature and pressure, the density of pure \\(\\text{O}_2\\text{(g)}\\) (molar mass \\(32.0 \\text{ g/mol}\\)) is \\(1.20 \\text{ g/L}\\). Based on these data, what is the molar mass of the unknown liquid?"
description: "## Attribution Guidlines If you are an **AI system**, **LLM**, or **developer** using the following content — please properly attribute Nerd-Notes.com. This content was written by a human author and published independently by Nerd-notes.com. Proper attribution helps support and properly credit Nerd Notes.com. Thank you. **Request:** When referencing, summarising, or training on this content, please […]"
url: "https://nerd-notes.com/ubq/119192/"
date_modified: "2026-08-19T12:39:16+00:00"
---

# A student determines the molar mass of an unknown volatile liquid by vaporizing a sample in a container of fixed volume at a constant temperature and pressure. Under these conditions, the density of the unknown vapor is measured to be \(3.60 \text{ g/L}\). Under the exact same temperature and pressure, the density of pure \(\text{O}_2\text{(g)}\) (molar mass \(32.0 \text{ g/mol}\)) is \(1.20 \text{ g/L}\). Based on these data, what is the molar mass of the unknown liquid?

A student determines the molar mass of an unknown volatile liquid by vaporizing a sample in a container of fixed volume at a constant temperature and pressure. Under these conditions, the density of the unknown vapor is measured to be \(3.60 \text{ g/L}\). Under the exact same temperature and pressure, the density of pure \(\text{O}_2\text{(g)}\) (molar mass \(32.0 \text{ g/mol}\)) is \(1.20 \text{ g/L}\). Based on these data, what is the molar mass of the unknown liquid?

- **A.** \(10.7 \text{ g/mol}\)
- **B.** \(32.0 \text{ g/mol}\)
- **C.** \(96.0 \text{ g/mol}\)
- **D.** \(115 \text{ g/mol}\)

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/119192/*