Free Mole to Grams, Grams to Moles Conversions Worksheets - Free Printable

Let's solve each problem step by step using the mole-to-grams and grams-to-moles conversion formula:

🔁 Key Formula:

$$
\text{moles} = \frac{\text{mass (g)}}{\text{molar mass (g/mol)}}
\quad \text{or} \quad
\text{mass (g)} = \text{moles} \times \text{molar mass (g/mol)}
$$

We'll use atomic/molecular masses from the periodic table:

| Element | Molar Mass (g/mol) |
|--------|---------------------|
| Ar | 39.95 |
| Mg | 24.31 |
| P | 30.97 |
| Li | 6.94 |
| S | 32.07 |
| Ca | 40.08 |
| Cr | 52.00 |
| As | 74.92 |
| Be | 9.01 |
| I | 126.90 |
| K | 39.10 |
| S | 32.07 |
| Na | 22.99 |
| F | 19.00 |
| Ca | 40.08 |
| P | 30.97 |
| O | 16.00 |
| H₂ | 2.02 (H₂ molecule) |
| Cl₂ | 70.90 (Cl₂ molecule)|

---

✔ Solutions:

#### 1. How many moles are in 22 grams of argon?
$$
\text{moles} = \frac{22}{39.95} \approx 0.551 \text{ mol}
$$

#### 2. How many grams are in 88.1 moles of magnesium?
$$
\text{mass} = 88.1 \times 24.31 \approx 2137.2 \text{ g}
$$

#### 3. How many moles are in 2.3 grams of phosphorus?
$$
\text{moles} = \frac{2.3}{30.97} \approx 0.0743 \text{ mol}
$$

#### 4. How many moles are in 15 grams of lithium?
$$
\text{moles} = \frac{15}{6.94} \approx 2.16 \text{ mol}
$$

#### 5. How many grams are in 2.4 moles of sulfur?
$$
\text{mass} = 2.4 \times 32.07 = 76.97 \text{ g}
$$

#### 6. How many moles are in 22 grams of argon?
Same as #1:
$$
\frac{22}{39.95} \approx 0.551 \text{ mol}
$$

#### 7. How many grams are in 88.1 moles of magnesium?
Same as #2:
$$
88.1 \times 24.31 \approx 2137.2 \text{ g}
$$

#### 8. How many moles are in 2.3 grams of phosphorus?
Same as #3:
$$
\frac{2.3}{30.97} \approx 0.0743 \text{ mol}
$$

#### 9. How many moles are in 9.8 grams of calcium?
$$
\frac{9.8}{40.08} \approx 0.244 \text{ mol}
$$

#### 10. How many moles are in 98.3 grams of aluminum hydroxide, Al(OH)₃?

First, calculate molar mass of Al(OH)₃:
- Al: 26.98
- O: 16.00 × 3 = 48.00
- H: 1.008 × 3 = 3.024
- Total = 26.98 + 48.00 + 3.024 = 78.004 g/mol

$$
\text{moles} = \frac{98.3}{78.004} \approx 1.26 \text{ mol}
$$

#### 11. How many grams are in 88.1 moles of magnesium?
Same as #2:
$$
88.1 \times 24.31 \approx 2137.2 \text{ g}
$$

#### 12. How many grams are in 11.9 moles of chromium?
$$
11.9 \times 52.00 = 618.8 \text{ g}
$$

#### 13. How many grams are in 238 moles of arsenic?
$$
238 \times 74.92 = 17,838.96 \text{ g} \approx 1.78 \times 10^4 \text{ g}
$$

#### 14. How many grams are in 2.4 moles of sulfur?
Same as #5:
$$
2.4 \times 32.07 = 76.97 \text{ g}
$$

#### 15. How many grams are in 0.02 moles of beryllium iodide, BeI₂?

Molar mass of BeI₂:
- Be: 9.01
- I: 126.90 × 2 = 253.80
- Total = 9.01 + 253.80 = 262.81 g/mol

$$
\text{mass} = 0.02 \times 262.81 = 5.256 \text{ g}
$$

#### 16. How many grams are in 3.3 moles of potassium sulfide, K₂S?

Molar mass of K₂S:
- K: 39.10 × 2 = 78.20
- S: 32.07
- Total = 78.20 + 32.07 = 110.27 g/mol

$$
\text{mass} = 3.3 \times 110.27 = 363.89 \text{ g}
$$

#### 17. How many grams are in 4.5 moles of sodium fluoride, NaF?

Molar mass of NaF:
- Na: 22.99
- F: 19.00
- Total = 41.99 g/mol

$$
\text{mass} = 4.5 \times 41.99 = 188.955 \text{ g}
$$

#### 18. How many grams are in $ 2.3 \times 10^{-4} $ moles of calcium phosphate, Ca₃(PO₄)₂?

Molar mass of Ca₃(PO₄)₂:
- Ca: 40.08 × 3 = 120.24
- P: 30.97 × 2 = 61.94
- O: 16.00 × 8 = 128.00
- Total = 120.24 + 61.94 + 128.00 = 310.18 g/mol

$$
\text{mass} = (2.3 \times 10^{-4}) \times 310.18 = 0.07134 \text{ g} \approx 7.13 \times 10^{-2} \text{ g}
$$

#### 19. Determine the mass of a molecule of hydrogen gas (H₂)

Hydrogen gas is diatomic: H₂
Molar mass of H₂ = 2 × 1.008 = 2.016 g/mol

But this is molar mass, not mass of one molecule.

To find mass of one molecule, use:
$$
\text{mass of one molecule} = \frac{\text{molar mass}}{N_A} = \frac{2.016 \text{ g/mol}}{6.022 \times 10^{23} \text{ molecules/mol}}
$$

$$
= 3.347 \times 10^{-24} \text{ g}
$$

✔ So, one molecule of H₂ has a mass of about $ 3.35 \times 10^{-24} $ grams

#### 20. Determine the mass of a molecule of chlorine gas (Cl₂)

Chlorine gas is Cl₂
Molar mass of Cl₂ = 2 × 35.45 = 70.90 g/mol

$$
\text{mass of one molecule} = \frac{70.90}{6.022 \times 10^{23}} = 1.177 \times 10^{-22} \text{ g}
$$

✔ So, one molecule of Cl₂ has a mass of about $ 1.18 \times 10^{-22} $ grams

---

✔ Final Answers Summary:

| Question | Answer |
|--------|--------|
| 1 | 0.551 mol |
| 2 | 2137.2 g |
| 3 | 0.0743 mol |
| 4 | 2.16 mol |
| 5 | 76.97 g |
| 6 | 0.551 mol |
| 7 | 2137.2 g |
| 8 | 0.0743 mol |
| 9 | 0.244 mol |
| 10 | 1.26 mol |
| 11 | 2137.2 g |
| 12 | 618.8 g |
| 13 | 17,839 g (or $1.78 \times 10^4$ g) |
| 14 | 76.97 g |
| 15 | 5.26 g |
| 16 | 363.9 g |
| 17 | 188.96 g |
| 18 | 0.0713 g (or $7.13 \times 10^{-2}$ g) |
| 19 | $3.35 \times 10^{-24}$ g |
| 20 | $1.18 \times 10^{-22}$ g |

Let me know if you'd like these rounded to significant figures or formatted differently!