Unit 8 - Solutions

Question 1

What is the solubility of Potassium Nitrate at 50 C?

Answer 1

86 g Potassium Nitrate

Question 2

Is the solution unsaturated, saturated, or supersaturated, if I have 30 g of Potassium Nitrate in 100 g of Water at 30 C?

Answer 2

Unsaturated

Question 3

Is the solution unsaturated, saturated, or supersaturated, if I have 60g of Potassium Nitrate in 100g of Water at 30 C?

Answer 3

Supersaturated

Question 4

How much solute will not dissolve if I have 80g of Potassium Nitrate in 100g of Water at 30C?

Answer 4

35g Potassium Nitrate

Question 5

How much more solute could I dissolve if I have 10g of Potassium Nitrate in 100g of Water at 30C?

Answer 5

~32g of Potassium Nitrate

Question 6

How much solute would crystallize out of solution once a solution of 85g of Potassium Nitrate in 100g of Water at 50C is cooled to 20C?

Answer 6

55g Potassium Nitrate

Question 7

Molarity

Answer 7

Expressions of Concentration ( [] )

The amount of a component in a given area or volume.

Question 8

Solute

Answer 8

The component being dissolved.

The component in the smallest amount.

Question 9

Solvent

Answer 9

The component doing the dissolving.

The component in the largest amount.

Water is the universal solvent.

Question 10

Concentrated

Answer 10

A relatively large amount of solute.

Question 11

Dilute

Answer 11

Relatively small amount of solute.

Question 12

Solution

Answer 12

Solute + Solvent

Question 13

How to determine if a solution is unsaturated, saturated, or supersaturated.

Answer 13

Add more solute and observe the results.

Question 14

Unsaturated

Answer 14

Contains less solute than it can at that temperature.

Question 15

Saturated

Answer 15

Contains as much solute as it can at that temperature.

If you add more solute it will not dissolve.

Question 16

Supersaturated

Answer 16

Contains more solute than it should at that temperature. Ussually the solution is heated to allow that much solute to dissolve and then cooled back down.

If you add solute to a supersaturated solution the “super” part (amount over the saturation point) will crystallize out of solution.

Question 17

Solubility Curve

Answer 17

Used to determine the mass of solute in 100g (100ml) of water at a given temperature.

Question 18

Molarity

Answer 18

M

Question 19

What is the molarity of a solution made by dissolving 2.5g of NaCl in enough water to make 125 ml of solution?

Answer 19

Question 20

Percent Mass

Answer 20

Question 21

Calculate the concentration of the solute in the diluted solution: 1.00mL of 0.50M NH4Cl diluted to 250.0mL

Answer 21

M₁V₁ = M₂V₂

M₁ = (M₂V₂)/(V₁)

M₁ = (0.5 M x 1 ml)/(250 ml)

M₁ = 0.0020M

Question 22

Calculate the volume required to prepare the diluted solution: Given 6.0M NaOH; need 5.0L of 0.10M NaOH.

Answer 22

M₁V₁ = M₂V₂

V₁ = (M₂V₂)/(M₁)

V₁ = 0.083L

Question 23

What is the molarity of a solution in which 58 g of NaCl are dissolved in 1.0 L of solution?

Answer 23

1.0 M

Question 24

What is the molarity of a solution in which 10.0 g of AgNO₃ is dissolved in 500 ml of solution?

Answer 24

0.118 M AgNO₃

Question 25

## Footnote How many grams of KNO₃ should be used to prepare 2.00 L of a .500 M solution?

Answer 25

## Footnote 101 g KNO₃

Question 26

## Footnote To what volume should 5.0 g of KCl be made in order to prepare a .25 M solution?

Answer 26

## Footnote 0.27 L KCl

Question 27

Colligative Properties

Answer 27

properties that depend on the concentration of solute, but not on the chemical identity of the solute. (Vapor Pressure Lowering, Boiling Point Elevation, Freezing Point Depression, and Osmotic Pressure)

Question 28

"Like Dissolves Like"

Answer 28

Not everything will dissolve in everything. Polar solvents dissolve polar solutes. Nonpolar solutes dissolve nonpolar solutes. Water is polar so it dissolves polar solutes.

Question 29

The Dissolving Process

Answer 29

1. The solvent surrounds the outer surface of the solute. 2. Individual Solute Ions are "stripped" away from the surface due to their attraction to the solvent particles. 3. This exposes more particles to the solvent and thus the process continues.

Question 30

How can you make things dissolve faster?

Answer 30

1. Agitation (stirring) 2. Temperature 3. Increase Surface Area (Grind or Crush)