Grams to Moles and Moles to Grams Practice Problems (with answer key)

Part 1: Moles to Grams (Elements)

Convert the given amount of moles into grams.

1. 2.00 mol of Helium
2. 0.75 mol of Copper 
3. 10.0 mol of Sulfur 
4. 0.15 mol of Silver 
5. 5.2 mol of Calcium 

Part 2: Grams to Moles (Elements)

Convert the given mass in grams into moles.

1. 24.31 g of Magnesium 
2. 100.0 g of Iron 
3. 5.00 g of Lithium 
4. 250.0 g of Gold 
5. 15.5 g of Potassium 

Part 3: Moles to Grams (Compounds)

Calculate the molar mass of the compound, then convert moles to grams.

1. 3.00 mol of water 
2. 0.50 mol of sodium chloride 
3. 1.20 mol of carbon dioxide 
4. 2.50 mol of CH4
5. 0.10 mol of H2SO4 

Part 4: Grams to Moles (Compounds)

Calculate the molar mass of the compound, then convert grams to moles.

1. 100.0 g of calcium carbonate 
2. 36.0 g of C6H12O6 
3. 50.0 g of NH3 
4. 117.0 g of sodium chloride 
5. 22.0 g of carbon dioxide 

Answer Key

Part 1: Moles to Grams (Elements)

1. 8.00 g
2. 47.66 g
3. 320.60 g
4. 16.18 g
5. 208.42 g

Part 2: Grams to Moles (Elements) 

1. 1.00 mol 
2. 1.79 mol 
3. 0.72 mol 
4. 1.27 mol 
5. 0.40 mol

Part 3: Moles to Grams (Compounds) 

1. 54.05 g 
2. 29.22 g 
3. 52.81 g 
4. 40.11 g 
5. 9.81 g

Part 4: Grams to Moles (Compounds) 

1. 1.00 mol 
2. 0.20 mol 
3. 2.94 mol 
4. 2.00 mol 
5. 0.50 mol