Solubility graph worksheet with questions on determining solution states and calculating solute amounts for saturation.

Let's solve each question step by step using the solubility graph provided in the worksheet. Since I can't see the actual image, I'll assume a standard solubility curve that includes common substances like KCl, KNO₃, NaCl, CaCl₂, Pb(NO₃)₂, Ce₂(SO₄)₃, and K₂Cr₂O₇.

We will use typical values from a standard solubility graph (which is commonly used in textbooks). Here are the approximate solubilities at various temperatures:

| Substance | Solubility at 10°C | Solubility at 20°C | Solubility at 35°C | Solubility at 50°C | Solubility at 60°C | Solubility at 70°C | Solubility at 80°C |
|----------|--------------------|--------------------|--------------------|--------------------|--------------------|--------------------|--------------------|
| KCl | ~30 g/100g H₂O | ~34 g/100g H₂O | ~38 g/100g H₂O | ~42 g/100g H₂O | ~45 g/100g H₂O | ~50 g/100g H₂O | ~51 g/100g H₂O |
| KNO₃ | ~20 g/100g H₂O | ~32 g/100g H₂O | ~50 g/100g H₂O | ~80 g/100g H₂O | ~110 g/100g H₂O | ~130 g/100g H₂O | ~160 g/100g H₂O |
| NaCl | ~35 g/100g H₂O | ~36 g/100g H₂O | ~37 g/100g H₂O | ~38 g/100g H₂O | ~39 g/100g H₂O | ~39 g/100g H₂O | ~39 g/100g H₂O |
| CaCl₂ | ~60 g/100g H₂O | ~70 g/100g H₂O | ~80 g/100g H₂O | ~100 g/100g H₂O | ~110 g/100g H₂O | ~120 g/100g H₂O | ~130 g/100g H₂O |
| Pb(NO₃)₂ | ~40 g/100g H₂O | ~50 g/100g H₂O | ~60 g/100g H₂O | ~70 g/100g H₂O | ~80 g/100g H₂O | ~90 g/100g H₂O | ~100 g/100g H₂O |
| Ce₂(SO₄)₃| ~10 g/100g H₂O | ~15 g/100g H₂O | ~20 g/100g H₂O | ~25 g/100g H₂O | ~30 g/100g H₂O | ~35 g/100g H₂O | ~40 g/100g H₂O |
| NaCl | ~36 g/100g H₂O | ~36 g/100g H₂O | ~37 g/100g H₂O | ~38 g/100g H₂O | ~39 g/100g H₂O | ~39 g/100g H₂O | ~39 g/100g H₂O |
| K₂Cr₂O₇ | ~12 g/100g H₂O | ~15 g/100g H₂O | ~20 g/100g H₂O | ~25 g/100g H₂O | ~30 g/100g H₂O | ~35 g/100g H₂O | ~40 g/100g H₂O |

Now let’s go through each question.

---

Questions 1–4: Determine if solution is unsaturated, saturated, or supersaturated

We compare the given amount of solute to the solubility at that temperature.

#### 1. 60 g KCl at 70°C
- Solubility of KCl at 70°C ≈ 50 g/100g water
- Given: 60 g > 50 g → Supersaturated
✔ Answer: Supersaturated

> Note: A supersaturated solution has more solute than can normally dissolve. This is unstable and may crystallize.

#### 2. 10 g KClO₃ at 60°C
- KClO₃ solubility at 60°C ≈ ~25 g/100g water (from typical data)
- Given: 10 g < 25 g → Unsaturated
✔ Answer: Unsaturated

#### 3. 80 g NaNO₃ at 10°C
- NaNO₃ solubility at 10°C ≈ ~80 g/100g water (approximate; actually around 80–85 g)
- Given: 80 g ≈ solubility → Saturated
✔ Answer: Saturated

#### 4. 70 g CaCl₂ at 20°C
- CaCl₂ solubility at 20°C ≈ 70 g/100g water
- Given: 70 g = solubility → Saturated
✔ Answer: Saturated

---

Questions 5–8: How many grams to make saturated solution?

Find solubility at given temp.

#### 5. Pb(NO₃)₂ at 10°C
- Solubility ≈ 40 g/100g water
✔ Answer: 40 g

#### 6. Ce₂(SO₄)₃ at 50°C
- Solubility ≈ 25 g/100g water
✔ Answer: 25 g

#### 7. NaCl at 20°C
- Solubility ≈ 36 g/100g water
✔ Answer: 36 g

#### 8. K₂Cr₂O₇ at 50°C
- Solubility ≈ 25 g/100g water
✔ Answer: 25 g

---

Questions 9–10: Underline the more concentrated solution

#### 9. At 10°C: saturated solution of KNO₃ or saturated solution of CaCl₂
- KNO₃ at 10°C ≈ 20 g/100g water
- CaCl₂ at 10°C ≈ 60 g/100g water
- So CaCl₂ is more concentrated

✔ Underline: saturated solution of CaCl₂

#### 10. At 50°C: saturated solution of KNO₃ or unsaturated solution of NaNO₃ with 90 g in 100 g water
- KNO₃ at 50°C ≈ 80 g/100g water → saturated = 80 g
- NaNO₃ at 50°C ≈ 110 g/100g water → so 90 g is unsaturated, but concentration = 90 g
- Compare:
- KNO₃ saturated: 80 g
- NaNO₃ unsaturated: 90 g
- 90 > 80 → NaNO₃ solution is more concentrated

✔ Underline: unsaturated solution of NaNO₃ consisting of 90 g dissolved in 100 g of water

---

Question 11: If 115 g KNO₃ added to 100 g water at 35°C, how many grams do not dissolve?

- Solubility of KNO₃ at 35°C ≈ 50 g/100g water
- Added: 115 g
- Can dissolve: 50 g
- Left undissolved: 115 − 50 = 65 g

✔ Answer: 65 grams do not dissolve

---

Question 12: What mass of KCl needed for saturated solution in 200 g water at 80°C?

- Solubility of KCl at 80°C ≈ 51 g/100g water
- For 200 g water:
$$
\frac{51\ \text{g}}{100\ \text{g water}} \times 200\ \text{g water} = 102\ \text{g}
$$

✔ Answer: 102 grams

---

✔ Final Answers:

1. Supersaturated
2. Unsaturated
3. Saturated
4. Saturated
5. 40 g
6. 25 g
7. 36 g
8. 25 g
9. saturated solution of CaCl₂
10. unsaturated solution of NaNO₃ consisting of 90 g...
11. 65 grams
12. 102 grams

---

💡 Note: These values are based on typical solubility curves. If your graph differs slightly (e.g., exact numbers), adjust accordingly by reading directly from the graph. But these are standard textbook approximations.

Let me know if you'd like help interpreting the actual graph or need a visual explanation!