Lesson 17: Multistep Conversions
MULTISTEP CONVERSIONS
EXAMPLES:
1. 10.5g of N2 gas are placed in a balloon at STP. Determine the volume of the balloon.
10.5g x 1 mol x 22.4 L = 8.40 L
28.0g 1 mol
2. How many Formula Units are there in 5.2 g of Manganese (II) Sulphide?
MnS
5.2g x 1 mol x 6.02x10^23 F.U. =3.5981 F.U.
87.0g 1 mol = 3.6 F.U.
3. A container of oxygen holds 40.1 L of methane gas at STP. How many molecules of methane is this?
40.1 L x 1 mol x 6.02x10^23 molecules = 1.0776 molecules
22.4 L 1 mol = 1.08 molecules
4. 2.6x10^22 chlorine atoms are present in a sample of chlorine gas. How many litres of gas at STP is this?
Cl2
2.6x10^22 atoms x 1 molecule x 1 mol x 22.4 L = 0.4837 L
2 atoms 6.02x10^23 molecules 1 mol = 0.48 L
5. A sample of CaCl2 occupies 8.50 L. How many Chlorine atoms are present in this sample?
8.50 L x 1 mol x 6.02x10^23 molecules x 2 atoms = 4.56875 x 10^23 atoms of Chlorine 22.4 L 1 mol 1 CaCl2 molecules = 4.57 x 10^23 atoms of Chlorine
~Kelly~