ACIDS, BASES, AND PH

pp. 39-44

NEED TO MEMORIZE THE FOLLOWING ELEMENTS AND COMPOUNDS FOR YOUR QUIZ AND TEST!ELEMENTS H: hydrogen O: oxygen N: nitrogen C: carbon Na: sodium Cl: chlorine K: potassium S: sulfur

COMPOUNDSH2O: waterNaCl: sodium chloride/saltH2SO4: sulfuric acidHCl: hydrochloric acidNaOH: sodium hydroxideCO2: carbon dioxideO2: oxygen gas

ACIDS AND BASES

H2O = water

H+ = hydrogen ion

H2O + H+ H3O +

OH- = hydroxide ion

WHAT IS AN ACID?osolution that has an excess of H+ ions.

oIt comes from the Latin word acidus that means "sharp" or "sour".

oThe more H + ions, the more acidic the solution.

PROPERTIES OF AN ACID

oTastes SouroCorrosiveowhich means they break down certain substances. Many acids can corrode fabric, skin,and paper

USES OF ACIDSoAcetic Acid = Vinegar

oCitric Acid = lemons, limes, & oranges. It is in many sour candies such as lemonhead & sour patch.

oAscorbic acid = Vitamin C which your body needs to function.

oFertilizers, steel, paints, and plastics.

oCar batteries

WHAT IS A BASE?

osolution that has an excess of OH- ions. oAnother word for base is alkali.

PROPERTIES OF A BASE

oFeel SlipperyoTaste BitteroCorrosive

USES OF BASESoCleaning products

oThe OH- ions interact strongly with certain substances, such as dirt and grease.

oChalk and oven cleaner are examples of familiar products that contain bases.

PH

omeasures acidity (from 0-14) and how much OH-/H+ is present. The closer to 0, the more the H+

0 -6 = acid

7 = neutral

7-14 = base

oCan use indicators to tell the pH (phenol red, pH paper, litmus, red cabbage)

PH SCALEoA change of 1 pH unit represents a tenfold change in the acidity of the solution.

oFor example, if one solution has a pH of 1 and a second solution has a pH of 2, the first solution is not twice as acidic as the second—it is ten times more acidic.