Molar Mass and Gas Laws

This video lesson covers the concept of moles in chemistry, focusing on how to determine the number of moles using mass and volume. It explains the analogy of counting M&Ms to understand counting atoms and molecules, introduces the use of the periodic table for calculating molar mass, and provides practice problems to reinforce learning. The lesson also covers the ideal gas law and its application at standard temperature and pressure (STP).

What is the main goal of this lesson?

• To learn how to see atoms with a microscope

• To understand the history of chemistry

• To calculate the molar mass and convert between mass, volume, and moles

• To memorize the periodic table

How can you determine the number of M&Ms in a bag without opening it?

• By shaking the bag and listening to the sound

• By dividing the mass of the M&Ms by the mass of one M&M

• By measuring the volume of the bag

• By counting them one by one

What is the gram formula mass (GFM) of CO2?

• 44 grams per mole

• 32 grams per mole

• 12 grams per mole

• 28 grams per mole

How many molecules are in one mole of a substance?

• 1.01 x 10^23

• 6.02 x 10^23

• 9.02 x 10^23

• 3.01 x 10^23

At STP, what volume does one mole of an ideal gas occupy?

• 11.2 liters

• 22.4 liters

• 44.8 liters

• 33.6 liters

Which two balloons will have the same volume if they contain the same number of molecules?

• Balloon A and B

• All balloons will have different volumes

• Balloon A and C

• Balloon B and C

What is the total volume occupied by a 2-gram sample of H2 gas at STP?

• 22.4 liters

• 44.8 liters

• 11.2 liters

• 33.6 liters

How many moles are in 576 grams of SO2 gas?

• 10 moles

• 9 moles

• 8 moles

• 6 moles

What is the GFM of SO2?

• 128 grams per mole

• 64 grams per mole

• 96 grams per mole

• 32 grams per mole

If two gases have the same number of moles, will they have the same mass?

• Yes, because they have the same volume

• No, because they have different molar masses

• Yes, because they are both gases

• No, because they have different colors