Name:______________________________Date:__________Period:_________

SOLUBILITY WORKSHEET

Use the solubility curves on the attached page to answer the following questions.

1. These solubility curves are based on the solubility (in grams) of various salts

dissolving in ____________ grams of water. In general for solids, as

temperature increases, the solubility of the salt ___________________________.

2. Most and least soluble at different temperatures:

a. Which salt is least soluble at 20oC?________

b. Which salt is most soluble at 10oC?_________

c. For which salt does the solubility change the least? ________________

3. How many grams of each solute below is needed to saturate 100g of water at 80 oC to prepare the following solutions?

a. KNO3___________________________

b. KCl_____________________________

c. NaCl____________________________

4. How many grams of each solute below are needed to make a saturated solution at 50 oC?

a. KClO3__________________________

b. NaNO3__________________________

c. KNO3___________________________

5. At what temperature are the following solutes equally soluble in 100g of water?

a. NaNO3 and KNO3 ___________

b. KNO3 and NaCl ___________

c. NaCl and KCl ___________

6. The quantity of solute per 100 g of water used in making some solutions is listed below. Is the solution saturated, unsaturated, or supersaturated?

Solute Temperature

a. 103 g KNO3 60 oC ____________________________

b. 40 g KCl 40 oC ____________________________

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c. 20 g KClO3 30 oC ____________________________

7. How much more solute must be added to keep the following solutions saturated at the temperature changes indicated?

a. NaCl 10 oC to 80 oC ________________

b. NaNO3 20 oC to 90 oC ________________

c. KNO3 50 oC to 60 oC ________________

8. How much solute will precipitate out (assuming no supersaturation occurs) for the following solutions over the temperature changes indicated?

a. NH4Cl 90 oC to 50 oC __________________

b. KClO3 50 oC to 28 oC __________________

c. KI 25 oC to 2 oC __________________

9. How many grams of solute are needed to make a saturated solution at 80 o in the quantities of water indicated? (hint: look at question #3 to help you)

a. ? grams of KNO3 in 200 grams of H2O ___________________________

b. ? grams of KCl in 300 grams of H2O _____________________________

c. ? grams of NaCl in 50 grams of H2O ____________________________

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Solubilities as a Function of Temperature

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Solve the following problems. Show your work and include correct units.

1. What is the molarity of a solution that contains 3.0 mol of KCl per 0.50 L of solution?

2. What is the molarity of a solution that contains 85.0 g of Na2SO4 in 325 mL of solution?

3. What is the molarity of a solution that contains 125 g of C2H5OH in 0.250 L of solution?

4. What mass of CH3OH is required to prepare 1.50 L of 3.00 M solution?

5. What mass of K3PO4 is required to prepare 4.00 L of a 1.50 M solution?

6. What mass of NaOH is required to prepare 3000 mL of 0.250 M solution?

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Dilution of Solutions

Directions: Acids and bases are usually purchased in concentrated form. Rarely, however, do we want to use the acid or base in its concentrated form – we must dilute it to the exact concentration we want. Use the table below to help you answer the following questions. As always, show your work!

Concentrated Solution Molarity of Concentrate (M)

Acetic Acid, Glacial (CH3COOH) 17.5Ammonium Hydroxide (NH4OH) 14.5

Formic Acid (HCOOH) 23.6Hydrochloric Acid (HCl) 12.1Hydrofluoric Acid (HF) 28.9

Nitric Acid (HNO3) 15.9Perchloric Acid, 60% (HClO4) 9.1Perchloric Acid, 70% (HClO4) 11.7

Phosphoric Acid (H3PO4) 14.8Potassium Hydroxide (KOH) 11.7Sodium Hydroxide (NaOH) 19.4

Sulfuric Acid (H2SO4) 18.0

1. What volume of concentrated hydrochloric acid is needed to make 3.0 L of 1.0 M HCl?

2. What volume of concentrated ammonium hydroxide is needed to make 250 mL of 0.5 M NH4OH?

3. What molarity of diluted sodium hydroxide would be obtained if 50.0 mL of concentrated solution was diluted to a final volume of 200.0 mL?

4. You mix 128 mL of an unknown, concentrated acid with water and get 1.54 L of a 1.5 M acid solution. What type of acid is it? Hint: Calculate M1 and compare to the table above!

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X Chemistry Name ________________________ Review Problems

Using you table of formulas in your notes and previously solved textbook problems, solve the following.

1. What is the molarity of a solution containing 14.6g of K2S dissolved in a total of 2.5L of solution?

2. What is the mole fraction of both water and HCl if 2.77g of HCl are dissolved in 150mL of water? (1g = 1mL for water only)

3. What is the molality of a solution that contains 12.4g of calcium fluoride (remember: Ca is +2 and F is -1) in 250g of water?

4. What is total volume of solute in a 2L solution that is 3.55% concentrated by volume?

5. How many grams of sodium hydroxide would you need to make 5 liters of a 2.75M solution?

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6. If a solution has a molality of 4.5 and the volume of water that was used to make that solution is 3,000mL, how many grams of sodium chloride (the solute) are contained in the solution?

7. How many milliliters of a 16M solution of sulfuric acid would be required to make 8L of 2.25M sulfuric acid?

8. What is the molality of a solution that contains 15.2g of AlCl3 in 400g of water?

9. How many liters of 0.55M KCl can you make if you only have 42.5g of KCl left for the rest of the school year?

10. How many liters of 0.85M HBr would you have if you diluted 20.0mL 4.5M HBr until you reached the dilute concentration?

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Concentration Practice Worksheet1) If I make a solution by adding water to 75 mL of ethanol until the total volume of the solution is

375 mL, what’s the percent by volume of ethanol in the solution? (Answer: 20%)

2) If I add 1.65 L of water to 112 grams of sodium acetate…

a) What is the molality of NaC2H3O2 in this solution? (Answer: 0.82)

b) What is the percent by mass of sodium acetate in this solution? (Answer: 6.36%)

c) What is the mole fraction of water in this solution? (Answer: 0.985)

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3. If I dilute 250 mL of 0.10 M lithium acetate solution to a volume of 750 mL, what will the concentration of this solution be? (Answer: 0.033 M)

4. How many grams of magnesium chloride (MgCl2) are needed to make 6.0 L of a 3.0 M solution? (Answer: 1715)

5. Calculate the molarity of the following solutions.

a. 12 g of lithium hydroxide (LiOH) in 1.0 L of solution (Answer: 0.55)

b. 198 g of barium bromide (BaBr2) in 2.0 L of solution (Answer: 0.33)

c. 54 g of calcium sulfide (CaS) in 3.0 L of solution (Answer: 0.25)

6. A test tube contains 10 mL of a 3.0 M CaCO3 solution. Calculate the number of grams of CaCO3 in the tube. (Answer: 3.0 g)