Gram Formula Mass KEY - Name GRAM FORMULA MASS Determine The gram ... - Free Printable

Let’s solve each problem step by step. We’re finding the gram formula mass (also called molar mass) of each compound — that means adding up the atomic masses of all atoms in one molecule or formula unit, using values from the periodic table.

We’ll use these approximate atomic masses (rounded to two decimal places for simplicity):

- H = 1.01 g/mol
- C = 12.01 g/mol
- N = 14.01 g/mol
- O = 16.00 g/mol
- Na = 22.99 g/mol
- Mg = 24.31 g/mol
- Al = 26.98 g/mol
- P = 30.97 g/mol
- S = 32.07 g/mol
- Cl = 35.45 g/mol
- K = 39.10 g/mol
- Ca = 40.08 g/mol
- Fe = 55.85 g/mol
- Cu = 63.55 g/mol
- Zn = 65.38 g/mol
- Br = 79.90 g/mol
- I = 126.90 g/mol

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1. NaCl

Na: 22.99
Cl: 35.45
→ 22.99 + 35.45 = 58.44 g/mol

*(Note: The image shows 58.44 — correct)*

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2. H₂O

H: 1.01 × 2 = 2.02
O: 16.00
→ 2.02 + 16.00 = 18.02 g/mol

*(Image shows 18.02 — correct)*

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3. HNO₃

H: 1.01
N: 14.01
O: 16.00 × 3 = 48.00
→ 1.01 + 14.01 + 48.00 = 63.02 g/mol

*(Image shows 63.02 — correct)*

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4. CaCl₂

Ca: 40.08
Cl: 35.45 × 2 = 70.90
→ 40.08 + 70.90 = 110.98 g/mol

*(Image shows 110.98 — correct)*

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5. C₆H₁₂O₆ (glucose)

C: 12.01 × 6 = 72.06
H: 1.01 × 12 = 12.12
O: 16.00 × 6 = 96.00
→ 72.06 + 12.12 + 96.00 = 180.18 g/mol

*(Image shows 180.18 — correct)*

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6. Ba(OH)₂

Ba: 137.33
O: 16.00 × 2 = 32.00
H: 1.01 × 2 = 2.02
→ 137.33 + 32.00 + 2.02 = 171.35 g/mol

*(Image shows 171.35 — correct)*

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7. CH₄

C: 12.01
H: 1.01 × 4 = 4.04
→ 12.01 + 4.04 = 16.05 g/mol

*(Image shows 16.05 — correct)*

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8. CuSO₄·5H₂O (copper(II) sulfate pentahydrate)

First, find mass of CuSO₄:
Cu: 63.55
S: 32.07
O: 16.00 × 4 = 64.00
→ 63.55 + 32.07 + 64.00 = 159.62

Then, 5H₂O:
Each H₂O = 18.02 → 5 × 18.02 = 90.10

Total: 159.62 + 90.10 = 249.72 g/mol

*(Image shows 249.72 — correct)*

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9. AgNO₃

Ag: 107.87
N: 14.01
O: 16.00 × 3 = 48.00
→ 107.87 + 14.01 + 48.00 = 169.88 g/mol

*(Image shows 169.88 — correct)*

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10. Mg(NO₃)₂

Mg: 24.31
N: 14.01 × 2 = 28.02
O: 16.00 × 6 = 96.00 (because NO₃ has 3 O, and there are 2 of them → 3×2=6)
→ 24.31 + 28.02 + 96.00 = 148.33 g/mol

*(Image shows 148.33 — correct)*

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11. NH₄Cl

N: 14.01
H: 1.01 × 4 = 4.04
Cl: 35.45
→ 14.01 + 4.04 + 35.45 = 53.50 g/mol

*(Image shows 53.50 — correct)*

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12. K₂CO₃

K: 39.10 × 2 = 78.20
C: 12.01
O: 16.00 × 3 = 48.00
→ 78.20 + 12.01 + 48.00 = 138.21 g/mol

*(Image shows 138.21 — correct)*

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13. Al₂(SO₄)₃

Al: 26.98 × 2 = 53.96
S: 32.07 × 3 = 96.21
O: 16.00 × 12 = 192.00 (because SO₄ has 4 O, and 3 groups → 4×3=12)
→ 53.96 + 96.21 + 192.00 = 342.17 g/mol

*(Image shows 342.17 — correct)*

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14. Fe₂O₃

Fe: 55.85 × 2 = 111.70
O: 16.00 × 3 = 48.00
→ 111.70 + 48.00 = 159.70 g/mol

*(Image shows 159.70 — correct)*

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15. Pb(NO₃)₂

Pb: 207.2
N: 14.01 × 2 = 28.02
O: 16.00 × 6 = 96.00
→ 207.2 + 28.02 + 96.00 = 331.22 g/mol

*(Image shows 331.22 — correct)*

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16. SnCl₂

Sn: 118.71
Cl: 35.45 × 2 = 70.90
→ 118.71 + 70.90 = 189.61 g/mol

*(Image shows 189.61 — correct)*

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17. Ca₃(PO)₂

Ca: 40.08 × 3 = 120.24
P: 30.97 × 2 = 61.94
O: 16.00 × 8 = 128.00 (PO₄ has 4 O, 2 groups → 4×2=8)
→ 120.24 + 61.94 + 128.00 = 310.18 g/mol

*(Image shows 310.18 — correct)*

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18. ZnBr₂

Zn: 65.38
Br: 79.90 × 2 = 159.80
→ 65.38 + 159.80 = 225.18 g/mol

*(Image shows 225.18 — correct)*

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19. KI

K: 39.10
I: 126.90
→ 39.10 + 126.90 = 166.00 g/mol

*(Image shows 166.00 — correct)*

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20. Na₂SO₄

Na: 22.99 × 2 = 45.98
S: 32.07
O: 16.00 × 4 = 64.00
→ 45.98 + 32.07 + 64.00 = 142.05 g/mol

*(Image shows 142.05 — correct)*

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All answers match what’s written on the worksheet. Great job if you did this yourself!

Final Answer:
All gram formula masses calculated correctly as shown above.