Solubility Curves (solutions, examples, activities, experiment ... - Free Printable

To solve the problem, we need to analyze the solubility curves provided in the image. The graph shows the solubility of different substances (potassium nitrate and others) in water as a function of temperature. Let's break down the solution step by step.

Step 1: Understand the Graph

- The x-axis represents the temperature in degrees Celsius.
- The y-axis represents the solubility in grams of solute per 100 grams of water.
- Different lines represent different substances:
- The black line represents potassium nitrate.
- Other lines represent other substances (labeled A, B, C, D, E).

Step 2: Identify Key Points

The problem likely involves determining solubility at specific temperatures or identifying which substance corresponds to a particular point on the graph. Since the task is not explicitly stated, I will infer common types of questions that can be asked based on such graphs.

#### Possible Questions and Solutions:

1. Question: What is the solubility of potassium nitrate at 50°C?
- Locate 50°C on the x-axis.
- Follow the vertical line up to the potassium nitrate curve (black line).
- Read the corresponding solubility value on the y-axis.
- At 50°C, the solubility of potassium nitrate is approximately 80 g/100 g water.

2. Question: Which substance has the highest solubility at 100°C?
- Locate 100°C on the x-axis.
- Observe the positions of all the curves at this temperature.
- The substance with the highest solubility at 100°C is represented by the topmost curve, which is labeled E.
- Therefore, substance E has the highest solubility at 100°C.

3. Question: At what temperature do substances A and B have the same solubility?
- Look for the point where the curves for substances A and B intersect.
- The intersection occurs at approximately 40°C.
- At 40°C, substances A and B have the same solubility.

4. Question: If you have a saturated solution of substance C at 60°C and cool it to 20°C, how much solute will precipitate out?
- At 60°C, the solubility of substance C is approximately 40 g/100 g water.
- At 20°C, the solubility of substance C is approximately 10 g/100 g water.
- The amount of solute that will precipitate out is the difference in solubility:
\[
40 \, \text{g} - 10 \, \text{g} = 30 \, \text{g}
\]
- Therefore, 30 g of solute will precipitate out.

Step 3: General Explanation

- Solubility Curves: These curves show how the solubility of a substance changes with temperature. Generally, solubility increases with temperature for most solids.
- Intersections: Points where two curves intersect indicate that the solubilities of the two substances are equal at that temperature.
- Saturated Solutions: A saturated solution contains the maximum amount of solute that can dissolve at a given temperature. Cooling a saturated solution can cause excess solute to precipitate out.

Final Answer

Since the exact task was not specified, I have provided solutions to common types of problems that can be solved using this graph. If you have a specific question in mind, please clarify, and I can refine the answer accordingly.

If the task was to identify the substance with the highest solubility at 100°C, the answer is:
\[
\boxed{E}
\]