Question 1:

According to the ideal gas law, which variable is directly proportional to the number of moles of gas?

Explanation: According to the ideal gas law, the number of moles of gas is directly proportional to the volume of the gas (assuming constant temperature and pressure).

Question 2:

What is the volume of 0.50 moles of nitrogen gas (N2) at a temperature of 25°C and a pressure of 1 atm?

Explanation: Using the ideal gas law equation PV = nRT and converting the temperature to Kelvin (25°C = 298 K), we can calculate the volume as V = (nRT)/P = (0.50 moles)(0.0821 L·atm/mol·K)(298 K)/(1 atm) ≈ 12.25 L ≈ 11.2 L (rounded to one decimal place).

Question 3:

A sample of hydrogen gas (H2) occupies a volume of 4.0 L at a temperature of 27°C and a pressure of 2 atm. How many moles of hydrogen gas are present?

Explanation: Using the ideal gas law equation PV = nRT and converting the temperature to Kelvin (27°C = 300 K), we can calculate the number of moles as n = (PV)/(RT) = (2 atm)(4.0 L)/(0.0821 L·atm/mol·K)(300 K) ≈ 0.098 mol ≈ 0.10 mol (rounded to two decimal places).

Question 4:

Under constant temperature and pressure, if the volume of a gas sample is doubled, how does the number of moles of gas change?

Explanation: According to Avogadro's law, under constant temperature and pressure, the volume of a gas is directly proportional to the number of moles of gas. Therefore, if the volume is doubled, the number of moles of gas also doubles.

Question 5:

At constant temperature and pressure, if the volume of a gas sample is halved, how does the pressure of the gas change?

Explanation: According to Boyle's law, at constant temperature, the pressure of a gas is inversely proportional to the volume of the gas. Therefore, if the volume is halved, the pressure of the gas doubles.