Leon M Goldstein High School For The Sciences



Name: ________________KEY__________________

Solubility (Table G):

1. The compound which is the most soluble at 20°C is ______KI___________________

2. The compound which is the least soluble at 10°C is ___________KClO3______________

3. The number of grams of potassium nitrate needed to saturate 100 mL of water at 70°C is ___134 g________________.

4. The formulas of the compounds which vary inversely with the temperature are _______SO2______, _________HCl_________ and _________NH3_________ .

5. 100 mL of a sodium nitrate solution is saturated at 10°C. How many additional grams are needed to saturate the solution at 50°C? 115g – 80g = 35 g

6. The two salts that have the same degree of solubility at 70°C are ____NaNO3______ and ___KNO3________

7. The salt with a solubility is least affected by a change in temperature is _______NaCl____________.

8. A saturated solution of potassium nitrate is prepared at 60°C using 200 mL of water. If the solution is cooled to 30°C, how many grams will precipitate out of the solution? 2 * (108 – 48) = 120

9. Explain the difference between saturated, unsaturated, and supersaturated solutions? Provide a real life example.

Saturated - a solution that has dissolved the maximum capacity of solute. ( Example; A restaurant that can seat 100 people seats 100 people)

Unsaturated – a solution that has the ability to dissolve more solute.( A restaurant that can seat 100 people has seated 40 people.)

Supersaturated – a solution that hold more than the maximum capacity it could hold. ( A restaurant that seats 100 people has seated 120 people so the boss comes in and kicks out 20 people.)

II) Molarity:

1. To make a 4.00 M solution, how many moles of solute will be needed if 12.0

liters of solution are required? ( 4.00 mol/ L) * (12 L) = 48 moles of solute

2. How many moles of sucrose are dissolved in 250 mL of solution if the solution

concentration is 0.150 M?

Convert to Liters! (.150 mol/ L) * (.250 L) = 0.6 moles of sucrose

3. What is the molarity of a solution of HNO3 that contains 12.6 grams HNO3 in 1.0 L of solution? Find moles.

12.6 grams / (63 g/mol) = 0.2 moles

0.2 mol/ 1.0 L = 0.2 M

4. How many grams of potassium nitrate are required to prepare 0.250 L of a

0.700 M solution? ( 0.700 mol / L) * (.250 L) =0 .175 moles

0.175 mol * (gram formula mass of KNO3) = grams of KNO3

5. How many liters of solution can be produced from 2.5 moles of solute if a 2.0 M

solution is needed? (2.5 moles / 2 mol/ L ) = 1.25 L

III) Concentration Percent by mass:

1. 10.8 g of sodium chlorate is dissolved in 85 g of water. Determine the percentage by mass of sodium chlorate in this solution.

(10.8 g / 85g ) * 100= 13 % sodium chlorate

2. 3.5 g of a barium sulfite is dissolved in 50.0 g of water. Determine the percentage by mass of barium sulfite in this solution.

(3.5g /53.5 g) * 100 = 6.5 % barium sulfite

3. 5.83 g magnesium oxide is dissolved in 20.0 g of water. Calculate the concentration of magnesium oxide expressed as percent by mass.

(5.83/ 35.83) * 100 = 16.3 %

4. How many grams of magnesium chloride is in 5.00 g of 6.00 % MgCl solution?

(5 g * 6/100 ) = 0.3 g

0.3 grams Magnesium chloride

Percent by volume:

5. If I make a solution by adding 83 grams of sodium hydroxide to 750 mL of water…What is the percent by mass of sodium hydroxide in this solution?

(83g / 833 mL ) * 100 = 9.9 %

6. If I make a solution by adding water to 35 mL of methanol (CH3OH) until the final volume of the solution is 275 mL…What is the percent by volume of methanol in this solution? (35 mL/ 275 mL) = 13 %

Parts per million:

7. 0.05 grams of sodium chloride is dissolved to make 0.05 g of solution.

(0.05 g / 0.5 g)* 106 =

8. 734 grams of lithium sulfate are dissolved to make 2500g of solution.

(734 g / 2500 g) * 106 = 0.29 ppm

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