Lecture 19.1a-Properties of Acids and Bases

Acids taste sour, will change the color ofan acid-base indicator, and can bestrong or weak electrolytes in aqueoussolution.

19.1

Citrus fruits contain citric acid.

Tea contains tannic acid.

19.1

Bases taste bitter, feel slippery, willchange the color of an acid-baseindicator, and can be strong or weakelectrolytes in aqueous solution.

19.1

Antacids use bases to neutralizeexcess stomach acid.

The base calcium hydroxide is acomponent of mortar.

The Arrhenius definition ofACIDS AND BASES

Acids dissociate to produce H+

HCl H+ + Cl-

Bases dissociate to produce OH-

NaOH Na+ + OH-

H+ and H3O+ mean the same thing

HCl H+ + Cl-

Or

HCl + H2O H3O+ + Cl-

H+ is a protonAcids form H+ which attaches towater forming the hydronium ion

H+ + H2O H3O+ hydronium ion

H+ and H3O+ mean the same thing

Acidic hydrogens are written firstin the chemical formula.

HNO3 = monoprotic acid

H2SO4 = diprotic acid

H3PO4 = triprotic acid

HC2H3O2 = monoprotic

protic aka proton

An acidic hydrogen can dissociatefrom the acid as H+.

19.1

Acetic acid

Stomach acid

Battery acid

In soda pop

Vinegar

Makes bubblesin carbonatedbeverages

Arrhenius Bases

Hydroxide ions are one of the products of thedissolution of an alkali metal in water.

19.1

19.1

Milk of magnesia is a base usedas an antacid.

When acids and bases are mixed theyreact to form water in a

Neutralization reaction

NaOH + HCl H2O + NaCl(aq)

An acid/base reaction always forms water and an aqueous salt

The net ionic equation for anacid/base reaction is

H+ + OH- H2O

PROPERTIES OF ACIDS AND BASES ACIDS BASES Produce H+ Produce OH-

pH below 7 pH above 7 Sour taste Bitter taste H+ + some metals = H2(g) Slippery feel Litmus paper red Litmus paper blue React with base to React with acid to form water and salt form water & salt

BOTH ACIDS AND BASES ARE ELECTROLYTES