3.5 Use of amount of substance in relation to volumes of gases

• At standard temperature and pressure (STP), the molar volume of a gas is 22.4
• Avogadro's Law applies only at constant temperature and pressure.


  True
• What is the universal gas constant denoted by?

  R
• Match the variable with its meaning in the molar volume formula:

  V ↔️ Volume of the gas

  n ↔️ Number of moles

  V_{m} ↔️ Molar volume
• The value of Avogadro's constant is approximately 6.022 x 10^23 particles per mole.


  True
• How much volume does 3 moles of oxygen gas occupy at STP?

  67.2 L
• What formula is used to calculate the volume of a gas using its amount in moles and molar volume?

  $V =$$n \times V_{m}$
• At standard temperature and pressure (STP), the molar volume of a gas is approximately 22.4 L/mol.
• At STP, the molar volume of a gas is approximately 22.4 L/mol.
• The number of moles in 44.8 L of carbon dioxide at STP is 2 moles.
• Avogadro's constant has a value of approximately 6.022 x 10^23 particles per mole.
• The molar volume of a gas at STP is 22.4 L/mol.
• The molar volume of a gas at STP is approximately 22.4 L/mol.
• What is the molar volume at STP in L/mol?

  22.4
• What is the molar volume in liters occupied by one mole of any gas at STP?

  22.4 L
• What are the conditions of STP?

  0 °C and 1 atm
• What does $V$ represent in the formula $V =$$n \times V_{m}$?


  Volume of the gas
• Calculate the volume occupied by 3 moles of oxygen gas at STP.

  67.2 L
• The molar volume of a gas at STP is 22.4 L/mol.


  True
• To calculate the number of moles using volume at STP, use the formula $n =$$\frac{V}{V_{m}}$, where $V_{m}$ is the molar volume
• The molar volume of a gas at STP is 22.4 L.


  True
• What is the formula for Avogadro's Law relating volume, moles, and molar volume?

  $V =$$n \times V_{m}$
• The molar volume of a gas at STP is approximately 22.4 L/mol.


  True
• What is the mathematical expression for Avogadro's Law showing proportionality between volume and moles?

  $V \propto n$
• The proportionality constant in Avogadro's Law is Avogadro's constant.

  True
• Calculate the volume occupied by 3 moles of oxygen gas at STP.

  $67.2 \text{ L}$
• If you have 89.6 L of oxygen gas at STP, you have 4 moles of the gas.


  True
• Avogadro's Law states that volume is directly proportional to the amount of substance in moles at constant temperature and pressure.


  True
• Avogadro's Law holds true only at constant temperature and pressure.

  True
• The formula to calculate the volume of a gas is $V =$$n \times V_{m}$


  True
• The formula to calculate the number of moles of a gas is $n =$$\frac{V}{V_{m}}$


  True
• What does the variable $R$ represent in the ideal gas law, $PV =$$nRT$?


  Universal gas constant
• Calculate the molar volume of a gas at 300 K and 2 atm.

  12.47 L/mol
• How many moles of hydrogen gas are produced if a reaction yields 56 liters at STP?

  2.5 moles
• What does Avogadro's Law state about the relationship between the volume of a gas and the amount of substance (in moles)?

  Directly proportional
• The proportionality constant in Avogadro's Law is Avogadro's constant
• What is the volume occupied by 3 moles of oxygen gas at STP?

  67.2 L
• Steps to calculate the number of moles using Avogadro's Law:

  1️⃣ Identify the volume of the gas at STP

  2️⃣ Use the molar volume formula to find the number of moles

  3️⃣ Substitute the known values

  4️⃣ Calculate the number of moles
• The molar volume of a gas at STP is the volume occupied by one mole
• Steps to calculate the volume of a gas using its molar volume at STP:

  1️⃣ Identify the number of moles of the gas

  2️⃣ Use the formula $V =$$n \times V_{m}$

  3️⃣ Substitute the known values

  4️⃣ Calculate the volume of the gas