Acids, Bases, and Solutions Chapter 7

What is a Solution?

Same properties throughout Contains a solvent and a solute Solutions Same properties throughout Contains a solvent and a solute

Solvent Does the Dissolving Water = Liquid

Solute The stuff that is dissolved Sugar

Kool-Aid Solvent = Water Solute = Sugar

Water is referred to as the “universal Solvent” Why?

Water dissolves almost anything

Concentration How much solute (dissolved stuff)

Dilute Weak Not a lot of solute (dissolved stuff)

Concentrated Strong A lot of solute (dissolved stuff)

Measuring Concentration Amount of Solute Amount of Solvent X 100

Example A solution contains 12 g of solute dissolved in 36 g of solution. What is its concentration?

Answer: 10% 12 g 36 g = .33 x 100 .33 = 33%

Example What is the concentration of a solutions that contains 45 grams of sugar in 500 grams of solution?

Answer: 9% 45 g 500 g = .09 x 100 .09 = 9%

Example How much sugar is dissolved in 500 grams of a solution if the solution is 70 percent sugar by mass?

Answer: 350g X 500 g 70%= .7 (500) = x X = 350g

Solubility A measure of how much solute (dissolved stuff) can dissolve

Unsaturated Solution Weak, Dilute Very little solute is added Add more sugar it will dissolve

Saturated Solution Perfect Amount No more solute will dissolve If you add more it will settle to the bottom

Supersaturated Add so much solute that it begins to pile up on the bottom of the container

Acids and Bases

Indicators Compounds that change color when it contacts an acid or a base

Properties of Acids Sour taste Reacts with metals (corrosive) Turns litmus paper red

Properties of Bases Bitter Taste Slippery Feel Turns Litmus paper Blue

Acids Produce Hydrogen Ions (H+) in water

Bases Produce Hydroxide ions (OH-) ions in water

Strengths of Acids and Bases The pH scale

The pH scale Range of numbers from 1-14

Ph < 7 ACIDIC H+ ions present The lower the number the stronger the acid (more H+ ions)

pH = 7 Neutral Not acidic or basic H+ = OH- ions

pH > 7 BASIC OH- ions present The higher the number the more basic

Neutralization A reaction between an acid and a base Salt and water produced

Neutralization

Check for Understanding

pH 1, pH 3 or pH 7 ? Which contains the highest concentration of Hydrogen ions? pH of 1

pH of 3 pH of 6 or pH of 3 Which is stronger? Which contains more H+ ions? pH of 3

pH of 14 pH 10 or pH 14 Which is a stronger base? Which has more OH- ions? pH of 14