Science Survey

ACIDS AND BASES

ACIDS Acids donate H+ ions to form

hydronium ions, H30+ when dissolved in water.

Acids have a pH of less than 7. pH= measure of the hydronium

concentration in a solution.

Acids taste sour and are corrosive. Examples of acids include lemon

juice (citric acid), carbonated drinks, hydrochloric acid (HCl), vinegar (acetic acid)

BASES Bases contain hydroxide ions, OH-,

or react with water to form hydroxide ions.

Bases accept hydrogen ions, H+ Bases are bitter, slippery

substances.

Bases have a pH greater than 7. Examples include: antacids,

detergents, bleach, ammonia, calcium hydroxide (lime), and baking soda.

Bleach is a basic solution that can either be used as a disenfectant, or to remove colors or stains.

Copyright Pearson Prentice Hall

Acids, Bases, and pH

The pH scale Chemists devised a measurement system

called the pH scale to indicate the concentration of H+ ions in solution.

The pH scale ranges from 0 to 14.

Acid-Base Concentration (pH) Acidic: pH 0–6.99 Basic: pH 7.01–14 Neutral: pH 7.00

Figure 2.13

Neutralization reactions In neutralization reactions, acids

and bases react together to form water and salt.

Ex) HCl + NaOH NaCl + H2O

acid base salt water Antacids are weak bases that

neutralize stomach acid.

Describing solutions Solutions can be acidic, basic, or neutral. Acidic solutions have [H3O+] > [OH-] Basic solutions have [OH-] > [H3O+] Neutral solutions have [H3O+] = [OH-] A substance that can act as an acid or

base, such as water, is said to be amphoteric.