DC-056, Preparation of Oxygen -Oxygen is prepared through the action of solid manganese dioxide on a solution of 6% aqueous hydrogen peroxide.
DC-075, Volume
versus Pressure in a Gas -Air is trapped in a syringe (an air piston).
By clamping the sealed syringe upright and adding weights to the plunger,
the pressure exerted on the trapped air is varied systematically. The mass
applied and the resulting volume are recorded. The data permit the determination
of a relationship between volume and pressure for a fixed mass of gas at constant
temperature.
DC-077, Determining
the Molar Mass of Butane -A sample of butane gas (isobutane) is obtained
from a disposable cigarette lighter. The lighter is weighed both before and
after the gas is withdrawn. The volume, temperature and pressure of the gas
are measured. From these four quantities, the molar mass of the gas is calculated.
This is shown as a lecture experiment, but can be performed as a student experiment
when balances of adequate sensitivity (0.001 g) are available.
DC-078, Determining the Molar Mass of a Vapor -A volatile liquid with a boiling temperature in the range of 70-90 °C is placed in a small, dry, weighed flask. The mouth of the flask is covered with aluminum foil. A small hole is pierced through the foil. The flask is heated in boiling water until the liquid boils, and for a few seconds thereafter. At that point, the entire space of the flask is filled with vapor at 100 °C. The flask is cooled, dried, and weighed. The volume of the flask is measured. From all these data, together with the barometric pressure, the molar mass of the volatile liquid is calculated.
DC-079, Molar Volume of a Gas -A meter of polished magnesium is weighed. Lengths of the ribbon are cut. The length of a small section is measured, and the mass calculated from the length. The small section is dissolved in acid such that all of the gas is captured in a buret. From the volume of the gas, the pressure, the temperature, and the mass of magnesium, the molar volume of magnesium is calculated. A microscale version of this experiment is available.
DC-085, Molar Volume Model -Students construct models of different shapes whose total volume is 22.4 L.
