Final answer:
The Dumas Method is a procedure for determining the molar mass of a volatile liquid by heating it in a flask to vaporize, then using the ideal gas law with the mass difference and flask volume.
Step-by-step explanation:
The Dumas Method for determining the molar mass of a volatile liquid involves heating a sample of the liquid in a flask with a tiny hole at the top. This process causes the liquid to vaporize into a gas, which escapes the flask. The experimental procedure includes weighing the empty flask, adding the volatile liquid, and then heating to convert the entire liquid into gas. After cooling, the flask is weighed again, and the mass of the vaporized liquid is calculated. The volume of the flask is known, and in conjunction with the measured mass and the ideal gas law (PV=nRT), the molar mass of the volatile liquid can be determined.
Experimental Procedure Steps
Weigh the empty flask.
- Add a known mass of the volatile liquid to the flask.
- Heat the flask to vaporize the liquid completely.
- Allow the flask to cool.
- Weigh the flask containing the vaporized liquid.
- Use the mass difference, the known volume of the flask, and the ideal gas law to calculate the molar mass of the volatile liquid.