Moles and Chemical Calculations

The video tutorial guides students through a lab on calculating moles of chalk. It covers finding the original and secondary mass of chalk, writing the chemical formula for calcium carbonate, and determining its gram formula mass. The tutorial explains converting between grams and moles, using gram formula mass, and converting between moles and molecules using Avogadro's number. It also covers converting between moles and liters using molar volume. The teacher provides guidance but encourages students to perform calculations independently.

What is the first step in the moles of chalk lab for students who were absent?

• Find the original mass of the chalk.

• Draw a picture of the chalk.

• Calculate the moles of chalk.

• Determine the chemical formula of chalk.

What is the chemical formula for chalk?

• CaCO3

• CaCl2

• CaO

• Ca(OH)2

How do you determine the gram formula mass of calcium carbonate?

• Divide the mass of oxygen by the mass of calcium.

• Multiply the masses of calcium, carbon, and oxygen.

• Add the masses of calcium, carbon, and oxygen from the periodic table.

• Subtract the mass of carbon from calcium.

What is the next step after finding the gram formula mass in the moles of chalk lab?

• Determine the chemical formula of chalk.

• Find the mass of the secondary chalk.

• Draw a picture of the chalk.

• Calculate the moles of chalk used.

How do you convert grams to moles?

• Divide by the gram formula mass.

• Multiply by the gram formula mass.

• Add the gram formula mass.

• Subtract the gram formula mass.

What is the gram formula mass of water (H2O)?

• 22 g/mol

• 16 g/mol

• 20 g/mol

• 18 g/mol

How do you convert moles to grams?

• Subtract the gram formula mass.

• Add the gram formula mass.

• Divide by the gram formula mass.

• Multiply by the gram formula mass.

What is Avogadro's number used for?

• Converting moles to molecules.

• Converting grams to moles.

• Converting liters to moles.

• Converting moles to grams.

What is the molar volume of a gas at standard temperature and pressure?

• 18.0 liters

• 20.0 liters

• 24.0 liters

• 22.4 liters

How do you convert liters to moles for a gas?

• Add the molar volume.

• Multiply by the molar volume.

• Subtract the molar volume.

• Divide by the molar volume.