Mole Fraction and Gas Laws

This video lesson, presented by Mr. Mark Anthony B. Laroya, covers the concept of partial pressure in chemistry. It explains how individual gases in a mixture contribute to the total pressure, using Dalton's Law of Partial Pressure. The lesson includes a sample problem involving oxygen and methane to demonstrate calculations of partial pressures and total pressure. It also introduces the concept of mole fraction and its application in determining partial pressures. The video concludes with a summary of the key points discussed.

What causes the pressure exerted by a gas in a container?

• The weight of the gas

• Collisions of gas molecules with the container walls

• The temperature of the gas

• The volume of the container

According to Dalton's Law, how is the total pressure of a gas mixture determined?

• By multiplying the partial pressures of all gases

• By dividing the total volume by the total number of moles

• By adding the partial pressures of all gases

• By subtracting the smallest partial pressure from the largest

In the sample problem, what is the molecular weight of methane used for calculations?

• 32 grams per mole

• 44 grams per mole

• 16 grams per mole

• 12 grams per mole

What is the ideal gas constant (R) value used in the sample problem?

• 8.314 joules per mole kelvin

• 0.08205 liter atmosphere per mole kelvin

• 0.0821 liter atmosphere per mole kelvin

• 1.987 calories per mole kelvin

Which of the following is NOT a component of the ideal gas equation used in the sample problem?

• Volume

• Pressure

• Mole fraction

• Temperature

How is the mole fraction of a gas in a mixture defined?

• The ratio of the gas's pressure to the total pressure

• The ratio of the gas's volume to the total volume

• The ratio of the gas's mass to the total mass

• The ratio of the gas's moles to the total moles

What is the mole fraction of oxygen in the sample problem involving mole fraction?

• 0.188

• 0.250

• 0.563

• 0.750

In the context of Dalton's Law, what does the mole fraction of a gas multiplied by the total pressure give?

• The total volume of the gas

• The partial pressure of the gas

• The average kinetic energy of the gas

• The total mass of the gas

What is the total pressure of the gas mixture in the sample problem using mole fraction?

• 0.281 atmosphere

• 0.841 atmosphere

• 1.00 atmosphere

• 1.12 atmosphere

What is the partial pressure of methane in the sample problem using mole fraction?

• 0.28 atmosphere

• 0.56 atmosphere

• 0.75 atmosphere

• 0.84 atmosphere