Module H Unit 5 (Lessons 1-3)

Acids, Bases, and Solutionspp. 263-305

1

Vocabulary• solution• solvent• solute• solubility• acid• base• indicator• pH scale

• dilute solution • concentrated

solution• saturated

solution • unsaturated

solution• neutralization

Solution - well-mixed mixture that contains a

solvent and a solute

Understanding Solutions

1. Solvent - substance present in largest amount; dissolves

other substances2. Solute - substance present in smallest amount; dissolved

by the solvent

Parts of a Solution

Water is the universal solvent because it can

dissolve most other solutes

*Very common solutionsEx. sugar water, soda, tea

*Life depends on water solutions: plants use nutrients dissolved in

water in soil, tree sap carries dissolved water to cells, blood, saliva, tears, reactions in cells

Solutions with Water

What is the solvent in this solution?

What is the solute?

What are the solvents and solutes in these solutions?

*A solution can be made of any combination of gases, liquids, or

solidsEx. Air - Gas + Gas

Antifreeze - Liquid + LiquidDental fillings - Solid + Liquid

Brass - Solid + Solid

Solutions without Water

Not all mixtures are solutions, but all

solutions are mixtures

A mixture containing small undissolved particles that

do not settle out

Colloids

Colloids

A mixture in which particles can be seen and easily separated by settling or

filtration

Suspensions

Unlike a solution it does not have the same properties

throughout; it contains visible particles that are

larger than the particles in solutions or colloids

Suspensions

Suspensions

Suspensions

Suspensions settle out upon standingEx. Muddy Water

Solutions Colloids Suspensions

Do not settle out

Do not settle out

Settle out upon standing

Pass unchanged

through filter paper

Pass unchanged

through filter paper

Separated by filter paper

Do not scatter light Scatter light Scatter light

Solutes lower the freezing point and raise the boiling point of the

solvent

Ex. freezing fresh water vs. salt water

Ex. car coolant and antifreeze

A measure of how much solute can dissolve in a

solvent at a given temperature

Solubility

When the amount of solute dissolved in a certain

amount of solvent differs

Solubility - Concentration

1. Dilute Solutions2. Concentrated

Solutions

Solubility - Concentration

Dilute solution - a mixture that has only a little solute dissolved in a certain amount of solvent

Solubility - Concentration

Concentrated solution - a mixture that has a lot of

solute dissolved in the solvent

Solubility - Concentration

To calculate concentration of a solution, compare the amount of solute to the amount of solution

and multiply by 100 %

Solubility - Concentration

Ex.10g/100g x 100% = 10%

Solubility - Concentration

Solubility - Concentration

Copper Nitrate Solutions

1. Saturated solution2. Unsaturated solution

Solubility - Saturation

Saturated solution - a solution in which no more solute can be dissolved

Solubility - Saturation

Solubility - SaturationUnsaturated solution - a solution in which more solute can added and

dissolved

Solubility - Saturation

Solubility - Saturation

Factors Affecting Solubility1. Pressure - higher pressure of

gas over solvent, the more gas can be dissolved

2. Solvents - “like dissolves like”3. Temperature - for most solids

solubility increases as temperature increases; however, gases are less soluble as temperature increases

Solvents Affect

Solubility

Temperature Affects Solubility

Acid - a compound with the following properties:

1. tastes sour2. corrosive to metals and carbonates3. turns blue litmus paper red

Acids

Name of Acid Use

Ascorbic Aid (Vitamin C) Nutrient in fruits for good health

Folic Acid Nutrient in leafy green vegetables

Nitric Acid & Phosphoric Acid Fertilizers

Muriatic Acid (Hydrochloric Acid) Clean bricks and mortar

Sulfuric Acid Batteries, refine petroleum, treat iron and steel

BasesBase - a compound with the

following properties:1. tastes bitter2. slippery3. turns red litmus paper blue4. neutralize acids

Name of Base Use

Calcium oxide & Calcium hydroxide Mortar & Cement

Calcium oxide Can also be added to make soil less acidic

Sodium hydroxide Drain cleaners

Ammonia Solutions Cleaners

Baking soda Carbon dioxide gas used to make breads rise

Bases

Acids and Bases in Solution

Hydrogen ions

Hydroxide ions

Indicator - used to determine if a

substance is acidic or basic; usually changes color

Indicators

Two Indicators1. Litmus Paper

2. pH Paper

Indicators

Litmus Paper as an Indicator

Based on the pH scale - range of values from 0 - 14 that is used to determine the

strength of acids and bases

pH Paper as an Indicator

What do you think “pH” represents?

pH Scale

pH Paper as an Indicator

Neutralization -a chemical reaction between

an acid and base that results in water and a salt

(and the acid is neutralized)

Types of Salts

See Fig. 22 on p. 247 in text

for names and uses of

common salts