3- solubility worksheet - Free Printable

Let's solve each question based on the solubility data table provided and the concepts of solubility curves.

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Given Table: Solubility in 100 g of Water

| Temperature (°C) | Copper Sulfate | Calcium Hydroxide | Sodium Carbonate | Lithium Chloride |
|------------------|----------------|--------------------|-------------------|------------------|
| 10 | 10 | 60 | 160 | 20 |
| 30 | 30 | 64 | 230 | 25 |
| 50 | 65 | 68 | 420 | 33 |
| 70 | 80 | 74 | 460 | 40 |
| 90 | 90 | 76 | 460 | 48 |

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Question 1:

> If 65g of copper sulfate is dissolved in 100g of water at 50°C, is the resulting solution saturated, unsaturated, or supersaturated?

- At 50°C, the solubility of copper sulfate is 65 g per 100 g water.
- You are dissolving exactly 65 g in 100 g water → this matches the solubility limit.

✔ Answer: Saturated
(At saturation, the maximum amount is dissolved.)

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Question 2:

> If 80g of calcium hydroxide is dissolved in 100g of water at 90°C, is the resulting solution saturated, unsaturated, or supersaturated?

- At 90°C, solubility of calcium hydroxide = 76 g per 100 g water.
- You are trying to dissolve 80 g, which is more than 76 g.

So, only 76 g can dissolve; the remaining 4 g will not dissolve.

But since you're asking about the solution formed:
- The solution contains 76 g dissolved, but you added 80 g → excess solid remains.
- This means the solution is at its maximum solubility.

✔ Answer: Saturated
(A supersaturated solution would have *more* than the normal solubility dissolved without precipitation — that’s unstable. Here, excess solid is present, so it's just saturated with undissolved solid.)

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Question 3:

> If 20g of lithium chloride is dissolved in 100g of water at 30°C, is the resulting solution saturated, unsaturated, or supersaturated?

- At 30°C, solubility of lithium chloride = 25 g per 100 g water.
- You are dissolving 20 g, which is less than 25 g.

✔ Answer: Unsaturated
(Less than the maximum amount is dissolved.)

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Question 4:

> How many grams of sodium carbonate can be dissolved in 100g of water at 70°C?

- From the table, at 70°C, solubility of sodium carbonate = 460 g per 100 g water.

✔ Answer: 460 grams

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Question 5:

> A saturated solution of copper sulfate contains 100g of water. If the saturated solution is cooled from 70°C to 30°C, how many grams of copper sulfate will precipitate? (how many grams can no longer dissolve?)

- At 70°C, solubility of CuSO₄ = 80 g / 100 g water
- At 30°C, solubility of CuSO₄ = 30 g / 100 g water

When cooled:
- Initially, 80 g dissolved at 70°C
- At 30°C, only 30 g can stay dissolved

So, the excess = 80 - 30 = 50 g

✔ Answer: 50 grams of copper sulfate will precipitate.

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Question 6:

> Which substance is most soluble at 10°C?

Look at solubilities at 10°C:

- Copper sulfate: 10 g
- Calcium hydroxide: 60 g
- Sodium carbonate: 160 g
- Lithium chloride: 20 g

The highest value is sodium carbonate at 160 g/100g water.

✔ Answer: Sodium carbonate

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Question 7:

> Which substance’s solubility is least affected by temperature?

Check how much solubility changes from 10°C to 90°C for each:

- Copper sulfate: 10 → 90 g → change of 80 g
- Calcium hydroxide: 60 → 76 g → change of 16 g
- Sodium carbonate: 160 → 460 g → change of 300 g
- Lithium chloride: 20 → 48 g → change of 28 g

Now compare the relative change:

But the question asks for least affected — so smallest change in solubility.

- Calcium hydroxide: +16 g
- Lithium chloride: +28 g
- Copper sulfate: +80 g
- Sodium carbonate: +300 g

Smallest change: Calcium hydroxide

Also note: Calcium hydroxide increases slightly, but very little compared to others.

Even though it increases, its solubility changes least.

✔ Answer: Calcium hydroxide

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✔ Final Answers:

1. Saturated
2. Saturated
3. Unsaturated
4. 460 grams
5. 50 grams will precipitate
6. Sodium carbonate
7. Calcium hydroxide

Let me know if you'd like a graph or explanation of why solubility behaves differently!