Chemistry Lesson

​Lesson 4.6: Properties of Solutions

Multiple Choice

When a gas loses energy and enters the liquid phase ...

• Evaporation occurs

• Condensation occurs

• Freezing occurs

• Melting occurs

Multiple Choice

In which state of matter are the molecules moving the slowest?

• Solid

• Liquid

• Gas

• All are equal

Multiple Choice

Which state of matter has defined volume but not shape?

• Solid

• Liquid

• Gas

​Solution Formation

• Dissolution Rate: The rate at which a solute dissolves​

  • Depends on several factors

    • Size of a solute: Smaller particles have a greater surface area to be touched by the solvent

    • Temperature: Increases the speed of molecules

    • Agitation​: Breaks apart clumps of solute and increases kinetic energy

Experience Chemistry | Lesson 4.6

​Solubility

• Every solvent has a limit to how much of a solvent it can dissolve

• Solubility: the amount of solute that can be added to a solvent in specific conditions

  • Three types of solutions

    • Unsaturated: the solution contains less than the maximum amount of solute

    • Saturated: The solution contains the exact amount of solute

    • Super Saturated: The solution contains more than the maximum amount of solute

      • Extra solute crystalizes in the container

Experience Chemistry | Lesson 4.6

​Supersaturation

• Supersaturation leads to the growth of crystals of the solute

  • By raising the temperature to induce higher solubility, you can eventually cool a solution with more dissolved than normal

  • Crystallization Can be induced with the addition of a seed crystal ​

Experience Chemistry | Lesson 4.6

Dropdown

You make a pitcher of kool aid. You use the normal amount of water but only use half of the packed and the liquid is light colored with no taste. This is an example of a ​

Select answer

Solution

Dropdown

You take the earlier pitcher of Kool aid and add an additional three packets to the pitcher. Kool aid powder is sitting on the bottom of the pitcher. This is an example of a ​

Select answer

Solution

Dropdown

You take the earlier pitcher of Kool aid and add water until all the koolaid powder dissolves, but the solution maintains a bright color and taste. This is an example of a ​

Select answer

Solution

​Solubility and Temperature

• The Temperature of a solution affects how much solute can be dissolved in it.

• Solubility Curve: a graph of the solubility as a function of temperature

  • Line tells you the amount of solubility at a given temperature

  • Can help predict when a solution may be unsaturated, saturated, or supersaturated

Experience Chemistry | Lesson 4.6

Multiple Choice

When the temperature of the solvent is 50° C, approximately how many grams of sodium acetate will dissolve?

• 10

• 50

• 100

• 150

​Solubility of Gases

• Gases work the opposite of solids

  • Increasing temperature causes less gas to be dissolved in a solvent

  • Causes many enviornmental problems

    • As water temperatures rise, less oxygen gas is able to be contained in the water

      • Hypoxic Zones: areas where the amount of oxygen in water is so low, animal life suffocates

Experience Chemistry | Lesson 4.6

​Solubility and Pressure

• Pressure has little effects on the solubility of liquids and solids, but can greatly change the solubility of gases

  • Solubility increases as the pressure of a solution increases​

Experience Chemistry | Lesson 4.6

​Henry's Law

• The mathematical relationship between Solubility and Pressure

  • Can be used to predict solubility at different pressures​

• S= solubility, P= Pressure​

  • You can use any unit for pressure, but both the Initial and final pressure need to be in the same un​its

Experience Chemistry | Lesson 4.6

​Henry's Law Sample Problem 1

• If the solubility of a gas in water is 0.77g/L at 3.5 atm of pressure, what is its solubility at 1.0 atm of pressure if the temperature remains constant?

  • Step 1: Identify the information you know

    • S₁ = 0.77 g/L

    • P₁ = 3.5 atm

    • S₂ = ?

    • P₂ = 1.0

  • Step 2: Substitute your known information into Henry's Law​ and solve for the unknown

Experience Chemistry | Lesson 4.6

Fill in the Blank

If the solubility of a gas in water is 0.77g/L at 3.5 atm of pressure, what is its solubility at 1.0 atm of pressure if the temperature remains constant? Your answer should contain two decimal places

​Henry's Law Sample Problem 2

• The solubility of a gas in water is 0.16 g/L at 104 kPa. What is the solubility when the pressure of the gas is increased to 288 kPa?

  • Step 1: Identify the information you know

    • S₁

    • P₁

    • S₂

    • P₂​

Experience Chemistry | Lesson 4.6

​Henry's Law Sample Problem 2

• The solubility of a gas in water is 0.16 g/L at 104 kPa. What is the solubility when the pressure of the gas is increased to 288 kPa?

  • Step 1: Identify the information you know

    • S₁ = 0.16

    • P₁ = 104

    • S₂ = ?

    • P₂ = 288

  • Step 2: Plug ​your values into Henry's law and Solve

Experience Chemistry | Lesson 4.6

Fill in the Blank

The solubility of a gas in water is 0.16 g/L at 104 kPa. What is the solubility when the pressure of the gas is increased to 288 kPa? Round your answer to 2 decimal places

​Types of Mixtures

• Mixtures are combinations of 2 or more different substances

  • Solutions are known as Homogenous mixtures

    • Have a uniform composition so you can't see the separate parts of them

  • Heterogenous Mixtures: mixtures that are not uniform in composition

Experience Chemistry | Lesson 4.6

​Heterogenous Mixtures

• Two types:

  • Colloids: small molecules are clumped together throughout a liquid medium

    • Example: Milk

  • Suspensions: a mixture where the particles will separate out on their own over time

    • Has larger particles

Experience Chemistry | Lesson 4.6

Multiple Choice

What is a mixture?

• The combination of two or more substances.

• An ingredient.

• A liquid.

• A gas.

Multiple Choice

Is tea a mixture or a solution?

• Mixture

• Solution

Multiple Choice

Is fruit salad a mixture or solution?

• Mixture

• Solution