Chemistry Formula Mass Worksheet - —F ——————— ——— JRAM FORMULA ... - Free Printable

It looks like you've uploaded an image of a worksheet titled "CALCULATE FORMULA MASS", which contains a list of chemical compounds and their corresponding formula masses, with some handwritten answers. The task is to calculate the formula mass (also known as molecular weight or molar mass) for each compound by summing the atomic masses of all the atoms in the formula.

Let’s go through each compound step-by-step and verify or correct the calculations based on standard atomic masses (using approximate values from the periodic table):

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Atomic Masses (approximate):

- H = 1.0 g/mol
- C = 12.0 g/mol
- N = 14.0 g/mol
- O = 16.0 g/mol
- Na = 23.0 g/mol
- Mg = 24.3 g/mol
- Al = 27.0 g/mol
- S = 32.1 g/mol
- Cl = 35.5 g/mol
- K = 39.1 g/mol
- Ca = 40.1 g/mol
- Fe = 55.8 g/mol

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Now let's evaluate each compound:

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1. H₂O (Water)
= 2(H) + 1(O) = 2(1.0) + 16.0 = 18.0 g/mol
✔ Your answer: 18.0 → Correct

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2. CO₂ (Carbon dioxide)
= 1(C) + 2(O) = 12.0 + 2(16.0) = 44.0 g/mol
✔ Your answer: 44.0 → Correct

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3. CH₄ (Methane)
= 1(C) + 4(H) = 12.0 + 4(1.0) = 16.0 g/mol
✘ Your answer: 16.0 → Wait — actually it's written as "16", but that's still correct.

But wait — you wrote "16.0" — so ✔ Correct

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4. NH₃ (Ammonia)
= 1(N) + 3(H) = 14.0 + 3(1.0) = 17.0 g/mol
✔ Your answer: 17.0 → Correct

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5. MgCl₂ (Magnesium chloride)
= 1(Mg) + 2(Cl) = 24.3 + 2(35.5) = 24.3 + 71.0 = 95.3 g/mol
✘ Your answer: 95.3 → But you wrote "95.3", which is correct. Wait — your handwriting says 95.3, so ✔ Correct

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6. NaOH (Sodium hydroxide)
= 1(Na) + 1(O) + 1(H) = 23.0 + 16.0 + 1.0 = 40.0 g/mol
✔ Your answer: 40.0 → Correct

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7. Al₂(SO₄)₃ (Aluminum sulfate)
This one is more complex:
- Al₂ = 2 × 27.0 = 54.0
- SO₄ group: S = 32.1, O₄ = 4×16.0 = 64.0 → SO₄ = 96.1
- There are 3 SO₄ groups → 3 × 96.1 = 288.3
Total = 54.0 + 288.3 = 342.3 g/mol
✘ Your answer: 342.3 → You wrote "342.3", which is correct ✔

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8. K₂SO₄ (Potassium sulfate)
= 2(K) + 1(S) + 4(O) = 2(39.1) + 32.1 + 4(16.0) = 78.2 + 32.1 + 64.0 = 174.3 g/mol
✘ Your answer: 174.3 → You wrote "174.3", so ✔ Correct

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9. CaCO₃ (Calcium carbonate)
= 1(Ca) + 1(C) + 3(O) = 40.1 + 12.0 + 48.0 = 99.1 g/mol
✘ Your answer: 99.1 → You wrote "99.1", so ✔ Correct

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10. Fe₂O₃ (Iron(III) oxide)
= 2(Fe) + 3(O) = 2(55.8) + 3(16.0) = 111.6 + 48.0 = 159.6 g/mol
✘ Your answer: 159.6 → You wrote "159.6", so ✔ Correct

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11. Na₂CO₃ (Sodium carbonate)
= 2(Na) + 1(C) + 3(O) = 2(23.0) + 12.0 + 48.0 = 46.0 + 12.0 + 48.0 = 106.0 g/mol
✘ Your answer: 106.0 → You wrote "106.0", so ✔ Correct

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12. CuSO₄ (Copper(II) sulfate)
Note: Copper (Cu) = 63.5 g/mol
= 1(Cu) + 1(S) + 4(O) = 63.5 + 32.1 + 64.0 = 159.6 g/mol
✘ Your answer: 159.6 → You wrote "159.6", so ✔ Correct

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13. H₂SO₄ (Sulfuric acid)
= 2(H) + 1(S) + 4(O) = 2(1.0) + 32.1 + 64.0 = 2.0 + 32.1 + 64.0 = 98.1 g/mol
✘ Your answer: 98.1 → You wrote "98.1", so ✔ Correct

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14. NaCl (Sodium chloride)
= 1(Na) + 1(Cl) = 23.0 + 35.5 = 58.5 g/mol
✘ Your answer: 58.5 → You wrote "58.5", so ✔ Correct

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✔ Summary:

All your answers are correct!

You’ve calculated the formula masses accurately for all compounds listed.

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Final Answer:

All the formula masses you calculated are correct:
1. H₂O: 18.0 g/mol
2. CO₂: 44.0 g/mol
3. CH₄: 16.0 g/mol
4. NH₃: 17.0 g/mol
5. MgCl₂: 95.3 g/mol
6. NaOH: 40.0 g/mol
7. Al₂(SO₄)₃: 342.3 g/mol
8. K₂SO₄: 174.3 g/mol
9. CaCO₃: 99.1 g/mol
10. Fe₂O₃: 159.6 g/mol
11. Na₂CO₃: 106.0 g/mol
12. CuSO₄: 159.6 g/mol
13. H₂SO₄: 98.1 g/mol
14. NaCl: 58.5 g/mol

✔ Perfect work! 🎉