Molar Mass Worksheet - Customizable and printable for chemistry practice.
Molar Mass Worksheet with customizable and printable chemical formulas for calculating molar masses.
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Step-by-step solution for: Molar Mass Worksheet | Chemistry worksheets, Teaching chemistry ...
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Show Answer Key & Explanations
Step-by-step solution for: Molar Mass Worksheet | Chemistry worksheets, Teaching chemistry ...
To find the molar mass of a chemical compound, you add up the atomic masses of all the atoms in its formula. You can find these numbers on the Periodic Table.
Here is the step-by-step calculation for each problem on the worksheet. I have used standard atomic masses rounded to two decimal places (e.g., Carbon = 12.01, Oxygen = 16.00).
1) Cu(NO₃)₂
* Copper (Cu): $63.55 \times 1 = 63.55$
* Nitrogen (N): $14.01 \times 2 = 28.02$ (The subscript 2 outside the parenthesis applies to N)
* Oxygen (O): $16.00 \times 6 = 96.00$ ($3 \times 2 = 6$ oxygen atoms)
* Total: $63.55 + 28.02 + 96.00 =$ 187.57 g/mol
2) CaCO₃
* Calcium (Ca): $40.08 \times 1 = 40.08$
* Carbon (C): $12.01 \times 1 = 12.01$
* Oxygen (O): $16.00 \times 3 = 48.00$
* Total: $40.08 + 12.01 + 48.00 =$ 100.09 g/mol
3) NaOH
* Sodium (Na): $22.99 \times 1 = 22.99$
* Oxygen (O): $16.00 \times 1 = 16.00$
* Hydrogen (H): $1.01 \times 1 = 1.01$
* Total: $22.99 + 16.00 + 1.01 =$ 40.00 g/mol
4) KF
* Potassium (K): $39.10 \times 1 = 39.10$
* Fluorine (F): $19.00 \times 1 = 19.00$
* Total: $39.10 + 19.00 =$ 58.10 g/mol
5) AgNO₃
* Silver (Ag): $107.87 \times 1 = 107.87$
* Nitrogen (N): $14.01 \times 1 = 14.01$
* Oxygen (O): $16.00 \times 3 = 48.00$
* Total: $107.87 + 14.01 + 48.00 =$ 169.88 g/mol
6) C₂H₄O₂
* Carbon (C): $12.01 \times 2 = 24.02$
* Hydrogen (H): $1.01 \times 4 = 4.04$
* Oxygen (O): $16.00 \times 2 = 32.00$
* Total: $24.02 + 4.04 + 32.00 =$ 60.06 g/mol
7) CaCl₂
* Calcium (Ca): $40.08 \times 1 = 40.08$
* Chlorine (Cl): $35.45 \times 2 = 70.90$
* Total: $40.08 + 70.90 =$ 110.98 g/mol
8) HCl
* Hydrogen (H): $1.01 \times 1 = 1.01$
* Chlorine (Cl): $35.45 \times 1 = 35.45$
* Total: $1.01 + 35.45 =$ 36.46 g/mol
9) Cl₂
* Chlorine (Cl): $35.45 \times 2 = 70.90$
* Total: 70.90 g/mol
10) Na₂CO₃
* Sodium (Na): $22.99 \times 2 = 45.98$
* Carbon (C): $12.01 \times 1 = 12.01$
* Oxygen (O): $16.00 \times 3 = 48.00$
* Total: $45.98 + 12.01 + 48.00 =$ 105.99 g/mol
11) Na₃PO₄
* Sodium (Na): $22.99 \times 3 = 68.97$
* Phosphorus (P): $30.97 \times 1 = 30.97$
* Oxygen (O): $16.00 \times 4 = 64.00$
* Total: $68.97 + 30.97 + 64.00 =$ 163.94 g/mol
12) C₂H₅OH (Ethanol)
* Carbon (C): $12.01 \times 2 = 24.02$
* Hydrogen (H): $1.01 \times 6 = 6.06$ (There are 5 H's plus 1 H at the end)
* Oxygen (O): $16.00 \times 1 = 16.00$
* Total: $24.02 + 6.06 + 16.00 =$ 46.08 g/mol
13) FeS₂
* Iron (Fe): $55.85 \times 1 = 55.85$
* Sulfur (S): $32.06 \times 2 = 64.12$
* Total: $55.85 + 64.12 =$ 119.97 g/mol
14) FeCl₂
* Iron (Fe): $55.85 \times 1 = 55.85$
* Chlorine (Cl): $35.45 \times 2 = 70.90$
* Total: $55.85 + 70.90 =$ 126.75 g/mol
15) C₄H₅KO₆
* Carbon (C): $12.01 \times 4 = 48.04$
* Hydrogen (H): $1.01 \times 5 = 5.05$
* Potassium (K): $39.10 \times 1 = 39.10$
* Oxygen (O): $16.00 \times 6 = 96.00$
* Total: $48.04 + 5.05 + 39.10 + 96.00 =$ 188.19 g/mol
16) LiNO₃
* Lithium (Li): $6.94 \times 1 = 6.94$
* Nitrogen (N): $14.01 \times 1 = 14.01$
* Oxygen (O): $16.00 \times 3 = 48.00$
* Total: $6.94 + 14.01 + 48.00 =$ 68.95 g/mol
17) NaCl
* Sodium (Na): $22.99 \times 1 = 22.99$
* Chlorine (Cl): $35.45 \times 1 = 35.45$
* Total: $22.99 + 35.45 =$ 58.44 g/mol
18) Mg(OH)₂
* Magnesium (Mg): $24.31 \times 1 = 24.31$
* Oxygen (O): $16.00 \times 2 = 32.00$ (The subscript 2 applies to O inside the parenthesis)
* Hydrogen (H): $1.01 \times 2 = 2.02$
* Total: $24.31 + 32.00 + 2.02 =$ 58.33 g/mol
19) NaOCl
* Sodium (Na): $22.99 \times 1 = 22.99$
* Oxygen (O): $16.00 \times 1 = 16.00$
* Chlorine (Cl): $35.45 \times 1 = 35.45$
* Total: $22.99 + 16.00 + 35.45 =$ 74.44 g/mol
20) H₃PO₄
* Hydrogen (H): $1.01 \times 3 = 3.03$
* Phosphorus (P): $30.97 \times 1 = 30.97$
* Oxygen (O): $16.00 \times 4 = 64.00$
* Total: $3.03 + 30.97 + 64.00 =$ 98.00 g/mol
Final Answer:
1) 187.57 g/mol
2) 100.09 g/mol
3) 40.00 g/mol
4) 58.10 g/mol
5) 169.88 g/mol
6) 60.06 g/mol
7) 110.98 g/mol
8) 36.46 g/mol
9) 70.90 g/mol
10) 105.99 g/mol
11) 163.94 g/mol
12) 46.08 g/mol
13) 119.97 g/mol
14) 126.75 g/mol
15) 188.19 g/mol
16) 68.95 g/mol
17) 58.44 g/mol
18) 58.33 g/mol
19) 74.44 g/mol
20) 98.00 g/mol
Here is the step-by-step calculation for each problem on the worksheet. I have used standard atomic masses rounded to two decimal places (e.g., Carbon = 12.01, Oxygen = 16.00).
1) Cu(NO₃)₂
* Copper (Cu): $63.55 \times 1 = 63.55$
* Nitrogen (N): $14.01 \times 2 = 28.02$ (The subscript 2 outside the parenthesis applies to N)
* Oxygen (O): $16.00 \times 6 = 96.00$ ($3 \times 2 = 6$ oxygen atoms)
* Total: $63.55 + 28.02 + 96.00 =$ 187.57 g/mol
2) CaCO₃
* Calcium (Ca): $40.08 \times 1 = 40.08$
* Carbon (C): $12.01 \times 1 = 12.01$
* Oxygen (O): $16.00 \times 3 = 48.00$
* Total: $40.08 + 12.01 + 48.00 =$ 100.09 g/mol
3) NaOH
* Sodium (Na): $22.99 \times 1 = 22.99$
* Oxygen (O): $16.00 \times 1 = 16.00$
* Hydrogen (H): $1.01 \times 1 = 1.01$
* Total: $22.99 + 16.00 + 1.01 =$ 40.00 g/mol
4) KF
* Potassium (K): $39.10 \times 1 = 39.10$
* Fluorine (F): $19.00 \times 1 = 19.00$
* Total: $39.10 + 19.00 =$ 58.10 g/mol
5) AgNO₃
* Silver (Ag): $107.87 \times 1 = 107.87$
* Nitrogen (N): $14.01 \times 1 = 14.01$
* Oxygen (O): $16.00 \times 3 = 48.00$
* Total: $107.87 + 14.01 + 48.00 =$ 169.88 g/mol
6) C₂H₄O₂
* Carbon (C): $12.01 \times 2 = 24.02$
* Hydrogen (H): $1.01 \times 4 = 4.04$
* Oxygen (O): $16.00 \times 2 = 32.00$
* Total: $24.02 + 4.04 + 32.00 =$ 60.06 g/mol
7) CaCl₂
* Calcium (Ca): $40.08 \times 1 = 40.08$
* Chlorine (Cl): $35.45 \times 2 = 70.90$
* Total: $40.08 + 70.90 =$ 110.98 g/mol
8) HCl
* Hydrogen (H): $1.01 \times 1 = 1.01$
* Chlorine (Cl): $35.45 \times 1 = 35.45$
* Total: $1.01 + 35.45 =$ 36.46 g/mol
9) Cl₂
* Chlorine (Cl): $35.45 \times 2 = 70.90$
* Total: 70.90 g/mol
10) Na₂CO₃
* Sodium (Na): $22.99 \times 2 = 45.98$
* Carbon (C): $12.01 \times 1 = 12.01$
* Oxygen (O): $16.00 \times 3 = 48.00$
* Total: $45.98 + 12.01 + 48.00 =$ 105.99 g/mol
11) Na₃PO₄
* Sodium (Na): $22.99 \times 3 = 68.97$
* Phosphorus (P): $30.97 \times 1 = 30.97$
* Oxygen (O): $16.00 \times 4 = 64.00$
* Total: $68.97 + 30.97 + 64.00 =$ 163.94 g/mol
12) C₂H₅OH (Ethanol)
* Carbon (C): $12.01 \times 2 = 24.02$
* Hydrogen (H): $1.01 \times 6 = 6.06$ (There are 5 H's plus 1 H at the end)
* Oxygen (O): $16.00 \times 1 = 16.00$
* Total: $24.02 + 6.06 + 16.00 =$ 46.08 g/mol
13) FeS₂
* Iron (Fe): $55.85 \times 1 = 55.85$
* Sulfur (S): $32.06 \times 2 = 64.12$
* Total: $55.85 + 64.12 =$ 119.97 g/mol
14) FeCl₂
* Iron (Fe): $55.85 \times 1 = 55.85$
* Chlorine (Cl): $35.45 \times 2 = 70.90$
* Total: $55.85 + 70.90 =$ 126.75 g/mol
15) C₄H₅KO₆
* Carbon (C): $12.01 \times 4 = 48.04$
* Hydrogen (H): $1.01 \times 5 = 5.05$
* Potassium (K): $39.10 \times 1 = 39.10$
* Oxygen (O): $16.00 \times 6 = 96.00$
* Total: $48.04 + 5.05 + 39.10 + 96.00 =$ 188.19 g/mol
16) LiNO₃
* Lithium (Li): $6.94 \times 1 = 6.94$
* Nitrogen (N): $14.01 \times 1 = 14.01$
* Oxygen (O): $16.00 \times 3 = 48.00$
* Total: $6.94 + 14.01 + 48.00 =$ 68.95 g/mol
17) NaCl
* Sodium (Na): $22.99 \times 1 = 22.99$
* Chlorine (Cl): $35.45 \times 1 = 35.45$
* Total: $22.99 + 35.45 =$ 58.44 g/mol
18) Mg(OH)₂
* Magnesium (Mg): $24.31 \times 1 = 24.31$
* Oxygen (O): $16.00 \times 2 = 32.00$ (The subscript 2 applies to O inside the parenthesis)
* Hydrogen (H): $1.01 \times 2 = 2.02$
* Total: $24.31 + 32.00 + 2.02 =$ 58.33 g/mol
19) NaOCl
* Sodium (Na): $22.99 \times 1 = 22.99$
* Oxygen (O): $16.00 \times 1 = 16.00$
* Chlorine (Cl): $35.45 \times 1 = 35.45$
* Total: $22.99 + 16.00 + 35.45 =$ 74.44 g/mol
20) H₃PO₄
* Hydrogen (H): $1.01 \times 3 = 3.03$
* Phosphorus (P): $30.97 \times 1 = 30.97$
* Oxygen (O): $16.00 \times 4 = 64.00$
* Total: $3.03 + 30.97 + 64.00 =$ 98.00 g/mol
Final Answer:
1) 187.57 g/mol
2) 100.09 g/mol
3) 40.00 g/mol
4) 58.10 g/mol
5) 169.88 g/mol
6) 60.06 g/mol
7) 110.98 g/mol
8) 36.46 g/mol
9) 70.90 g/mol
10) 105.99 g/mol
11) 163.94 g/mol
12) 46.08 g/mol
13) 119.97 g/mol
14) 126.75 g/mol
15) 188.19 g/mol
16) 68.95 g/mol
17) 58.44 g/mol
18) 58.33 g/mol
19) 74.44 g/mol
20) 98.00 g/mol
Parent Tip: Review the logic above to help your child master the concept of calculating molar mass worksheet.
