Theory - Unit 7 - Solutions

Question 1

Intermolecular Forces

Answer 1

Attractive forces BETWEEN molecules.

Van Der Waals or London Dispersion Forces are the weakest type of intermolecular force and hydrogen bonds are the strongest.

Question 3

What is the solubility of Potassium Nitrate at 50 C?

Answer 3

86 g Potassium Nitrate

Question 4

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

Answer 4

Unsaturated

Question 5

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

Answer 5

Supersaturated

Question 6

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

Answer 6

35g Potassium Nitrate

Question 7

What is the solubility of Potassium Nitrate at 50 C?

Answer 7

86 g Potassium Nitrate

Question 8

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

Answer 8

~32g of Potassium Nitrate

Question 9

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

Answer 9

Unsaturated

Question 10

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

Answer 10

Supersaturated

Question 11

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

Answer 11

35g Potassium Nitrate

Question 12

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 12

55g Potassium Nitrate

Question 13

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

Answer 13

Add more solute and observe the results.

Question 14

Solute

Answer 14

The component being dissolved.

The component in the smallest amount.

Question 15

Solvent

Answer 15

The component doing the dissolving.

The component in the largest amount.

Water is the universal solvent.

Question 16

Concentrated

Answer 16

A relatively large amount of solute.

Question 17

Dilute

Answer 17

Relatively small amount of solute.

Question 18

Intramolecular Forces

Answer 18

Attractive forces WITHIN a molecule (Ionic & Covalent Bonds)

These bonds are stronger than intermolecular forces.

Question 19

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

Answer 19

Add more solute and observe the results.

Question 20

Unsaturated

Answer 20

Contains less solute than it can at that temperature.

Question 21

Saturated

Answer 21

Contains as much solute as it can at that temperature.

If you add more solute it will not dissolve.

Question 22

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

Answer 22

Question 23

Supersaturated

Answer 23

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 27

Solubility Curve

Answer 27

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

Question 29

Molarity

Answer 29

Expression of Concentration ( [] )

Question 35

The Dissolving Process

Answer 35

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 36

What is the effect of pressure on solubility?

Answer 36

Question 37

What is the effect of temperature on solubility?

Answer 37

Question 44

Solution

Answer 44

Solute + Solvent

Question 50

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

Answer 50

101 g KNO₃

Question 51

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

Answer 51

0.27 L KCl

Question 52

Colligative Properties

Answer 52

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 54

How can you make things dissolve faster?

Answer 54

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

Question 57

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

Answer 57

1.0 M

Question 58

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

Answer 58

0.118 M AgNO₃

Question 59

“Like Dissolves Like”

Answer 59

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 63

immiscible

Answer 63

Will not dissolve in water.

Question 64

miscible

Answer 64

Will dissolve in water.