SCH4C Unit 2
Date: ________________________________
Calculations Involving the Mole
I.
Calculations involving Atoms
1. Calculate the mass, in grams, of 2.00 mol of calcium atoms.
2. Calculate the mass of 0.200 mol of nitrogen atoms.
3. (a) What amount of gold is in a 275.8 g nugget of pure gold?
(b) how many atoms of gold are there in a 275.8 g nugget of pure gold?
4. What amount of helium is in a balloon that contains 1.60 g of helium gas?
5. How many atoms of sulphur are in a 230.0 g sample of pure sulphur?
II.
Calculations involving molecules and compounds
1. Sodium fluoride is added to toothpaste and tap water to help prevent tooth decay. Calculate the mass of 2.00
mol of sodium fluoride, NaF.
2. Calculate the mass of 11.7 mol of ozone, O3 (g).
3. (a) Iron (III) oxide, Fe2O3, is more commonly known as rust. What amount of iron (III) oxide is in a 77.2 g
sample?
(b) How many formula units of the ionic compound iron (III) oxide are in 77.2 g of iron (III) oxide?
4. What amount of propane, C3H8(g), is in a tank that is filled with 5.00 kg of propane?
5. Calcium hydroxide, Ca(OH)2(s), is an ionic compound that is used to make slaked lime, a substance that is
used as a top-coat on the walls of many homes. How many formula units of calcium hydroxide are in a
sample of slaked lime that contains 250.0 g of calcium hydroxide?
III.
Calculating the number of atoms from the mass of molecules
1. Sand is composed of silicon dioxide, SiO2(s). How many atoms of oxygen are in a bag of pure sand, which
contains 1.00 kg of silicon dioxide?
2. One form of solid sulphur is composed of S8(s) molecules. How many atoms of sulphur are in an 18.0 g chunk
of solid sulphur?