Acids, Bases, & Salts

Chapter 25

Acids & Bases

Section 1

Acidscontains at least 1 hydrogen atom that

can be removed when acid is dissolved in water forming hydronium ions

Properties of acidsTaste sourCorrosive and can damage skin or

tissueReact with an indicator such as litmus

paper to produce a predictable color change

Common AcidsFoods contain acids.

Citrus fruits have citric acid.Yogurt and buttermilk have lactic

acid.Vinegar, or acetic acid, is in pickled

foods.The stomach uses hydrochloric

acid.

Four acids are vital to industry.Sulfuric acid

used in car batteries & in making fertilizers.Phosphoric acid

used to make detergents, fertilizers, & soft drinks.

Nitric acid used to make fertilizers & explosives.

Hydrochloric acid Used to clean steel

Baseforms hydroxide ions in a water solutionaccepts hydronium ions from acids

Properties of basesCrystalline solids in undissolved stateFeel slippery in solutionStrong bases are corrosiveReact with indicators to produce

predictable color changes; litmus paper turns blue

Uses of Common bases cleaning products, medications, fabrics,

and deodorants.

Solutions of acids and basesAcid describes compounds that can be

ionized in water to form hydronium ionsBase describes compounds that can form

hydroxide ions in solutionSolutions of acids & solutions of bases

are electric conductors to some extent

Strength of Acids & Bases

Section 2

strength of an acid or base depends on how completely a compound

separates into ions when dissolved in waterstrong acid

ionizes almost completely in solution.weak acid

only partly ionizes in solution.strong base

dissociates completely in solution.weak base

does not ionize completely.

Strong acids and bases conduct more electricity than weak ones.

Equations for strong acids & bases use a single arrow, indicating ions are formed

Equations for weak acids & bases use double arrows in opposite directions, indicating an incomplete reaction

Dilute and concentrated are terms to describe the amount of acid or base dissolved

pH - a measure of the concentration of H ions in a solution or how acidic or basic it is.pH lower than 7 means acidic.pH greater than 7 means basic.pH exactly 7 indicates a neutral solution.

pH is determined using a universal indicator paper or a pH meter.

Blood contains buffers which keep the pH balanced at about 7.4

Salts

Section 3

Neutralization chemical reaction between an acid and a base

taking place in a water solutionSalt

compound formed when negative ions from an acid combine with positive ions from base

also form when acids react with metalsSalt is essential for many animalsOther salt uses

manufacturing of paint, rubber, glass, soap, detergents, and dry cell batteries

Titration used to determine the concentration of an acidic

or basic solution.

Process of Titration:

1. Standard solutionA solution of known concentration

2. IndicatorWhat is added to the unknown solution.

3. End pointWhen a color change persists

Soaps organic salts with polar and nonpolar ends. Nonpolar hydrocarbon end interacts with oil and dirt Polar end helps oil and dirt dissolve in water

Detergents form more soluble salts with the ions in hard water and

reduce soap scum; can cause other environmental problems

Esters from alcohols, aren’t bases but have hydroxyl group used in fruit flavorings and perfumes

Polyesters synthetic fibers used to make fabrics