Solubility Curve Worksheet with Questions Based on Graph

Let's go through each question step by step using the Solubility Curve Graph provided.

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Understanding the Graph:

- The x-axis is temperature in °C (from 20°C to 90°C).
- The y-axis is solubility in grams per 100g of water.
- Three solids are plotted:
- Solid A: Steeply increasing curve → high solubility with temperature.
- Solid B: Moderately increasing curve.
- Solid C: Nearly flat line → very low and constant solubility.

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Answers with Explanations:

#### 1. What is the Solubility of Solid A at 40°C?
- Locate 40°C on the x-axis.
- Go up to the Solid A curve.
- Read the y-value: approximately 80 g per 100g of water.

✔ Answer: 80 g/100g water

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#### 2. What is the Solubility of Solid B at 30°C?
- Find 30°C on the x-axis.
- Go up to Solid B curve.
- Read the y-value: about 60 g per 100g of water.

✔ Answer: 60 g/100g water

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#### 3. What is the Solubility of Solid C at 60°C?
- At 60°C, follow the Solid C curve.
- It’s nearly flat — stays around 35–40 g.
- From graph: approximately 35 g per 100g of water.

✔ Answer: 35 g/100g water

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#### 4. How much of Solid A will dissolve in 100g of water at 80°C?
- Find 80°C on x-axis.
- Go up to Solid A curve.
- Read y-value: about 160 g per 100g water.

✔ Answer: 160 g

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#### 5. How much of Solid B will dissolve in 100g of water at 40°C?
- Find 40°C.
- Go up to Solid B curve.
- Value is about 70 g per 100g water.

✔ Answer: 70 g

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#### 6. Which Solid is the LEAST soluble at 60°C?
- Compare all three at 60°C:
- Solid A: ~120 g
- Solid B: ~80 g
- Solid C: ~35 g

→ Solid C has the lowest solubility.

✔ Answer: Solid C

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#### 7. Which Solid is MOST soluble at 60°C?
- Same comparison:
- Solid A: ~120 g
- Solid B: ~80 g
- Solid C: ~35 g

→ Solid A is most soluble.

✔ Answer: Solid A

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#### 8. At what temperature is the solubility of Solid A and Solid B the same?
- Find where the Solid A and Solid B curves intersect.
- They cross near 50°C.
- At this point, both have solubility of about 80 g/100g water.

✔ Answer: 50°C

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#### 9. Saturated - Unsaturated - Supersaturated: Solution that contains 70g of Solid B at 30°C?
- At 30°C, solubility of Solid B = 60 g/100g water (from Q2).
- The solution has 70g, which is more than the maximum that can dissolve.
- So it’s supersaturated if it’s stable, but typically such a solution would crystallize out excess.

However, since 70g > 60g, and assuming no extra conditions, it's not possible without special handling.

But based on standard definitions:
- If more than solubility limit is dissolved → Supersaturated (if stable)
- But usually, excess precipitates → Saturated with undissolved solid.

But here, the question says "contains 70g" — implies it's dissolved?

So if 70g is dissolved in 100g water at 30°C, and solubility is only 60g, then:

✔ Answer: Supersaturated

> Note: This is an unstable state; normally, excess would not stay dissolved.

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#### 10. Saturated - Unsaturated - Supersaturated: Solution that contains 110g of Solid A at 70°C?
- At 70°C, solubility of Solid A ≈ 140 g/100g water (from graph).
- 110g < 140g → less than maximum that can dissolve.

So the solution can dissolve more → Unsaturated.

✔ Answer: Unsaturated

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#### 11. How does temperature affect the solubility of solutions?
- Look at the trend for Solid A and B: solubility increases with temperature.
- Solid C is nearly constant.
- For most solids, solubility increases with temperature.

So correct choice is:

✔ b. As temperature increases, solubility increases

> Note: This is general for most solids (especially ionic compounds). Gases behave oppositely.

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✔ Final Answers Summary:

| Question | Answer |
|--------|--------|
| 1 | 80 g/100g water |
| 2 | 60 g/100g water |
| 3 | 35 g/100g water |
| 4 | 160 g |
| 5 | 70 g |
| 6 | Solid C |
| 7 | Solid A |
| 8 | 50°C |
| 9 | Supersaturated |
| 10 | Unsaturated |
| 11 | b. As temperature increases, solubility increases |

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Let me know if you'd like a labeled version of the graph or help interpreting other parts!