# Worksheet: Masses and Moles

Q1:

There is approximately 1 g of graphite in a pencil. How many moles of carbon atoms are there in 1.0 g of graphite?

Q2:

Which of the following is furthest from a mole of molecules/formula units?

• A 20.01 g hydrogen fluoride
• B 100.09 g calcium carbonate
• C 154.99 g cobalt(II) sulfate
• D 79.90 g bromine gas
• E 16.04 g methane

Q3:

Which of the following is furthest from a mole of atoms?

• A 15.999 g
• B 79.904 g
• C 10.81 g
• D 7.023 g
• E 24.305 g

Q4:

Which of the following contains the greatest number of moles of oxygen atoms?

• A
• B
• C
• D
• E

Q5:

Which of these has the greatest mass?

• A
• B
• C
• D
• E

Q6:

When 10.00 g of water partially evaporates, water molecules are removed as vapor. Calculate the mass of water remaining.

Q7:

Calcium carbonate has the formula .

What is the mass of one mole of calcium carbonate to the nearest gram?

What is the mass of one formula unit of calcium carbonate to 3 significant figures?

• A g
• B g
• C g
• D g
• E g

Calculate to 3 significant figures the number of moles present in 500 g of pure calcium carbonate.

Q8:

Which of the following represents the greatest mass?

• A 2.00 mol of calcium oxide
• B 110 g of calcium
• C molecules of oxygen gas
• D 3 mol of calcium
• E 80 L of oxygen gas at 1.00 bar and 298 K

Q9:

A packet of an artificial sweetener contains 40.0 mg of saccharin , which has the structural formula:

Saccharin has a molar mass of 183.18 g/mol.

How many saccharin molecules are there in the packet of artificial sweetener?

• A
• B
• C
• D
• E

How many carbon atoms are there in this quantity of saccharin?

• A
• B
• C
• D
• E