# Molar Mass of a Gas

The label on a cylinder of a noble gas became illegible, so a student allowed some of the gas to flow into a gas bulb with a volume of 0.3000 L until the pressure was 0.901 atm. The sample then weighed 1.45 g and its temperature was 27.0 $^{\circ}$C. What is the molar mass of the gas? Which noble gas is it?

## Related Problems

A student collected a gas in an apparatus connected to an open end manometer. The difference in heights of mercury in the two columns was 102 mm and the atmospheric pressure was measured to be 756 mmHg. What was the pressure of the gas in the apparatus in atm?

A sample of nitrogen has a volume of 883 mL and a pressure of 741 torr. What pressure will change the volume to 655 mL at the same temperature?

One procedure used to separate the isotopes of uranium to obtain material to construct a nuclear weapon employs uranium compound with the formula UF$_6$ . The compound boils at about 56 $^{\circ}$C, so at 100 $^{\circ}$C it is a gas. What is the density of 1.00 mol of UF$_6$ at 100 $^{\circ}$C if the pressure of the gas is 0.974 atm. (MM of U = 352.0 g/mol)

Suppose a 1.25 g sample of CaCO$_3$ is decomposed by heating. How many milliliters of CO$_2$ gas will be evolved if it will be measured at 0.974 atm and 25 $^{\circ}$C (MM of CaCO$_3$ = 100.05 g/mol)

CaCO$_3$ (s) $\longrightarrow$ CO$_2$ (g) + CaO (s)