# Molar Mass Practice

Use the periodic table to find the molar masses of the following compounds, then check your answers by clicking ANSWER.

HCl

1.0 g/mol + 35.5 g/mol

= 36.5 g/mol

K2CO3

2(39.1 g/mol) + 12.0 g/mol + 3(16.0 g/mol)

= 138.2 g/mol

Ca(OH)2

40.1 g/mol + 2(16.0 g/mol) + 2(1.0 g/mol)

= 74.1 g/mol

Na3PO4

3(23.0 g/mol) + 31.0 g/mol + 4(16.0 g/mol)

= 164.0 g/mol

Work each of the following problems.

1. How many atoms are in 6.2 moles of aluminum?

2. Convert 5.3 x 1025 molecules of CO2 to moles.

3. How many formula units of sodium acetate are in 0.87 moles of sodium acetate?

4. Convert 3.55 moles NaCl to formula units.

5. Convert 3.00 moles As2S3 to grams.

6. How many moles are represented by 11.5 g of C2H5OH?

7. What is the mass of 9.30 moles of SiH4?

8. Convert 8.00 x 1020 molecules of H2 to moles.

9. How many atoms of tin are found in 3.50 moles of tin?

10. How many grams of tin are found in 3.50 moles of tin?

Bonus: How many atoms of hydrogen are found in 12.6 moles of water?

Check your solutions by downloading the solutions. If you missed the problem, be sure to identify where you went wrong. On graded work, it is very important that you show all of the steps of your work. This will allow you to receive partial credit.

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