A 1.00 L flask is filled with 1.25 g of argon at 25 ∘C. A sample of ethane vapor is added to the same flask until the total pressure is 1.450 atm.

A) What is the partial pressure of argon, PAr, in the flask?
B) What is the partial pressure of ethane, Pethane, in the flask?

A 118-mL flask is evacuated and found to have a mass of 97.129 g. When the flask is filled with 768 torr of helium gas at 35$^{\circ} \mathrm{C}$, it has a mass of 97.171 g. Was the helium gas pure?

A sample of $N_2O$ effuses from a container in 42 seconds. How long will it take the same amount of gaseous 12 to effuse from the same container under identical conditions?

A flask with a volume of 1.50 L, provided with a stop-cock, contains ethane gas $\left(C_{2} H_{6}\right)$ at 300 K and atmospheric pressure ($1.013 \times 10^{5}Pa$). The molar mass of ethane is 30.1 g/mol. The system is warmed to a temperature of 550 K, with the stopcock open to the atmosphere. The stopcock is then closed, and the flask is cooled to its original temperature. (a) What is the final pressure of the ethane in the flask? (b) How many grams of ethane remain in the flask?

Oxygen gas reacts with powdered aluminum according to the reaction: $4 \mathrm{Al}(s)+3 \mathrm{O}_{2}(g) \longrightarrow 2 \mathrm{Al}_{2} \mathrm{O}_{3}(s)$ What volume of $O_2$ gas (in L), measured at 782 mmHg and 25$^{\circ} \mathrm{C}$, completely reacts with 53.2 g Al?

A gas mixture with a total pressure of 745 mm Hg contains each of the following gases at the indicated partial pressures: $CO_2$, 125 mmHg; Ar, 214 mmHg; and $O_2$, 187 mmHg. The mixture also contains helium gas. What is the partial pressure of the helium gas? What mass of helium gas is present in a 12.0-L sample of this mixture at 273 K?