Reading Solubility Curves Green

Reading Solubility Curves Green

What mass of solute will dissolve in 100mL of water at the following temperatures?

1. / KNO3at 70°C
2. / NaCl at 100°C
3. / NH4Cl at 90°C

Interpret which of the three substances is most soluble in water at 15°C.

Determine the molarity of a saturated NaCl solution at 25°C.

What term - saturated, unsaturated, or supersaturated - best describes:

· a solution that contains 70g of NaNO3 per 100 mL H2O at 30°C

· a solution that contains 60g of dissolved KCl per 100 mL H2O at 80°C

Interpreting Types of Solutions

On a solubility curve, the lines indicate the concentration of a solution

- the maximum amount of solute that will dissolve at that specific temperature.

Values on the graph below the curve line represent solutions

- more solute could be dissolved at that temperature.

Label the following solutions as saturated or unsaturated.

Solution / Saturated or Unsaturated? / If unsaturated: How much more solute can dissolve in the solution?
a solution that contains 70g of NaNO3 at 30°C (in 100 mL H2O)
a solution that contains 50g of NH4Cl at 50°C (in 100 mL H2O)
a solution that contains 20g of KClO3 at 50°C (in 100 mL H2O)
a solution that contains 70g of KI at 0°C (in 100 mL H2O)

Reading Solubility Curves Red

You'll notice that for most substances, solubility increases as temperature increases.

Can you find any exceptions on the graph?______

Here's an example of how to read the graph. Find the curve for KClO3.

At 30°C approximately 10g of KClO3 will dissolve in 100g of water. If the temperature is increased to 80°C, approximately ______of the substance will dissolve in 100g (or 100mL) of water.

1) What mass of solute will dissolve in 100mL of water at the following temperatures?

a. KNO3 at 70°C = ______

b. NaCl at 100°C= ______

c. NH4Cl at 90°C= ______

2) Which of the above three substances is most soluble in water at 15°C. = ______

Interpreting Types of Solutions

On a solubility curve, the lines indicate the concentration of a solution

- the maximum amount of solute that will dissolve at that specific temperature.

Values on the graph below the curve line represent solutions

- more solute could be dissolved at that temperature.

Label the following solutions as saturated or unsaturated.

Solution / Saturated or Unsaturated?
a solution that contains 70g of NaNO3 at 30°C (in 100 mL H2O)
a solution that contains 50g of NH4Cl at 50°C (in 100 mL H2O)
a solution that contains 20g of KClO3 at 50°C (in 100 mL H2O)
a solution that contains 70g of KI at 0°C (in 100 mL H2O)

Analyzing Solubility Curves

1. What is the solubility of KCl at 5°C? ______

What is the solubility of KCl at 25°C? ______

What is the solubility of Ce2(SO4)3 at 10°C? ______

What is the solubility of Ce2(SO4)3 at 50°C? ______

2. At 90°C, you dissolved 10 g of KCl in 100. g of water.

Is this solution saturated or unsaturated? How do you know?

3. A mass of 100 g of NaNO3 is dissolved in 100 g of water at 80ºC.

Is the solution saturated or unsaturated?______

As the solution is cooled, at what temperature should solid first appear in the solution? Explain.

4. Solubility:

Which compound is most soluble at 20 ºC? ______

Which is the least soluble at 40 ºC? ______

Which substance least soluble at 10°C? ______

5. A mass of 80 g of KNO3 is dissolved in 100 g of water at 50 ºC. The solution is heated to 70ºC.

How many more grams of potassium nitrate must be added to make the solution saturated? Explain your reasoning

Formula / If the following amounts of solute are dissolved in 100 mL of water: Is the solution SATURATED OR UNSATURATED
NaCl / 3 grams dissolved at 0ºC
KI / 120 grams dissolved at 0ºC
Ce(SO4)3 / 7.2 grams dissolved at 70ºC
NH4Cl / 11 grams dissolved at 46.7ºC

Analyzing Solubility Curves

1. What is the solubility of KCl at 5°C? ______

What is the solubility of KCl at 25°C? ______

What is the solubility of Ce2(SO4)3 at 10°C? ______

What is the solubility of Ce2(SO4)3 at 50°C? ______

2. At 90°C, you dissolved 10 g of KCl in 100. g of water.

Is this solution saturated or unsaturated? How do you know?

3. A mass of 100 g of NaNO3 is dissolved in 100 g of water at 80ºC.

Is the solution saturated or unsaturated?______

4. Solubility:

Which compound is most soluble at 20 ºC? ______

Which is the least soluble at 40 ºC? ______

Which substance least soluble at 10°C? ______

Analyzing Solubility Curves

What is the solubility of potassium nitrate in 100 grams of water at 60oC?

What is the solubility of potassium chloride in 100 grams of water at 60oC?

What is the solubility of sodium chloride in 100 grams of water at 90oC?

What is the minimum temperature needed to dissolve 65g of potassium nitrate in 100 grams of water?

What is the minimum temperature needed to dissolve 35g of potassium chloride in 100 grams of water?

At what temperature do potassium chloride and potassium nitrate have the same solubility?

At what temperature do potassium nitrate and sodium chloride have the same solubility?

If 20g of potassium chlorate are mixed with 100g of water at 40oC, how much will not dissolve?

If 200g of potassium nitrate are mixed with 100g of water at 70oC, how much will not dissolve?

If 50g of sodium chloride are mixed with 100g of water at 90oC, how much will not dissolve?

If 75g of NaNO3 are added to 100g of H2O at 35oC, how much more must be added to be saturated?

If 120g of KI are added to 100 grams of H2O at 15oC, how much more must be added to be saturated?

If 10g of NaCl are added to 100g of water at 100oC, how much more must be added to be saturated?

100 grams of water are saturated with sodium nitrate at 30oC.

If this solution is heated to 60oC, how much more can be dissolved?

100 grams of water are saturated with potassium nitrate at 0oC.

If the solution is heated to 65oC, how much more can be dissolved?

Which two substances have the same solubility at 75oC?

100 grams of water at 70oC are saturated with potassium chlorate.

If this solution is cooled to 25oC, how much of the solid will precipitate?

At what temperature do sodium nitrate and potassium nitrate have the same solubility?

How much potassium nitrate will dissolve in 50 grams of water at 50oC?

How much potassium nitrate will dissolve in 10 grams of water at 50oC?

Graph a Solubility Curve

Sodium Chloride Solubility

Temperature
(C) / Solubility
(g of solute/100 mL of H20)
0 / 35.7
10 / 35.8
20 / 35.9
30 / 36
40 / 36.4
60 / 37.1
80 / 38
90 / 38.5
100 / 39.2

Copper Sulfate Solubility

Temperature / Solubility
(g of solute/100 mL of H20)
0 / 23
10 / 27.5
20 / 32
30 / 38
40 / 44.5
60 / 62
80 / 84
100 / 114

Reading & Interpreting Solubility Curves

What mass of solute will dissolve in 100mL of water at the following temperatures?

1. / KNO3at 70°C
2. / NaCl at 100°C
3. / NH4Cl at 90°C

Interpret which of the three substances is most soluble in water at 15°C.

Determine the molarity of a saturated NaCl solution at 25°C.

Label the following solutions as saturated, unsaturated, or supersaturated.