Acids are electrolytes that: þ Produce H + (as H 3 O + ) ions in water – always listed first in the formula þ Turn blue litmus red þ Taste sour þ Corrode metals þ Neutralizes bases to form salts and water þ Low pH (1-6)

Examples of Acids Vinegar Acetic acid Carbonated Drinks Carbonic acid Vitamin C Ascorbic acid

Bases are electrolytes that: Produce OH - ions in water Taste bitter Burns skin (caustic) Feel soapy, slippery Neutralizes acids to form salts and water High pH (8 – 14) Turns litmus paper blue

Examples of Bases Soaps Ammonia Cleaner Drain cleaners Baking soda Lye Tums - antacids

Litmus paper tests Blue litmus paper turns red in acids Red litmus paper turns blue in bases

When an acid combines with a base, a neutralization reaction occurs making salt plus water. Acid + Base ---  Salt + Water Negative ions of acid combine with Positive ions of base. Example: HCl + NaOH --  NaCl + H 2 O

Characteristics of Salt pH of 7 pH hydrion paper turns green Is an electrolyte in solution (can conduct an electric current) Evaporate salt water solution, salt crystals will form MANY different kinds of salts Magnesium sulfate salt

Strengths of acids and bases Strengths of acids and bases Strong electrolytes are completely dissociated into ions in water. Weak acids and bases do not completely ionize. Strong acids completely dissociate in water, forming H+ and an anion. There are six strong acids. The others are considered to be weak acids. HCl - hydrochloric acid HNO 3 - nitric acid H2SO4 - sulfuric acid Strong bases dissociate 100% into the cation and OH- (hydroxide ion). The hydroxides of the Group I and Group II metals usually are considered to be strong bases. LiOH - lithium hydroxide NaOH - sodium hydroxide KOH - potassium hydroxide

Dilute vs. Concentrated To dilute an acid or a base, you add water. You can dilute a strong acid, HCl by adding water. 10 ml of HCl plus: * 100 ml of water, it is concentrated. -It is a concentrated, strong acid. * 1000ml of water, it is dilute. -It is a dilute, strong acid.