Acids, Bases Acids, Bases

and pHand pH

1. Acids1. Acids

Any compound that GIVES OFF Any compound that GIVES OFF H+H+ ionsions in solution in solution Ex. Ex. HClHCl H+H+ and Cl- and Cl-

TraitsTraits:: SourSour ex. ex. Juices, Juices, vinegar, HClvinegar, HCl

Add water

2. Bases2. Bases

Any compound that GIVES OFF Any compound that GIVES OFF OH-OH- ionsions in solution in solution Ex. Ex. NaOHNaOH Na+ and Na+ and OH-OH-

Traits:Traits: SlipperySlippery

Ex. Ex. SoapsSoaps, detergent, , detergent, ammoniaammonia

Add water

3. Neutralization Equal amountsEqual amounts of of acidacid and and basebase together together

Acid (H+)Acid (H+)

++ Base (OH-)Base (OH-)

HOHHOH = = HH2OO

A’sA’s and and B’sB’s make make saltssalts when you have when you have samesame amounts amounts

Ex. Ex. HCl (Hydrochloric acid)HCl (Hydrochloric acid) + + NaOH (Sodium NaOH (Sodium

hydroxide)hydroxide) H H22O (water) + NaCl (table salt)O (water) + NaCl (table salt)

4. BUFFERS substances that react with

strong acids or bases to prevent prevent sudden pH changesudden pH change

What do you take when stomach What do you take when stomach is upset?? (HINT: What digestive is upset?? (HINT: What digestive factor is in the stomach??)factor is in the stomach??) AntacidsAntacids (made of calcium (made of calcium

carbonate…a weak base!)carbonate…a weak base!)

5. pH 5. pH scale scale

• measures the concentration strength of acids and bases. – pH 0-6.9 = acid

• Strong acids 1-3

– pH 7.1-14 = base• Strong base pH 11 - 14

– pH 7 = neutral (water)

VIDEO: (3:49)

http://www.brainpop.com/science/matterandchemistry/phscale/

• Tests for Acids or bases• Turns Red = acidic• Turns Blue = basic

6. Litmus paper6. Litmus paper

Let’s Practice ……pH Let’s Practice ……pH activityactivity

YOU TRY:YOU TRY: Go to my website. Click on Go to my website. Click on Living Environment Living Environment Homepage.Homepage. Then click on the link for Then click on the link for The Biochemistry The Biochemistry PagPage.e. Go to Go to pH activitypH activity and complete and complete eacheach activity. activity.

Go to a computer and use the site below to conduct an investigation on acids and bases.

pH Scale activity

Watch VIDEO: (3:49)

http://www.brainpop.com/science/matterandchemistry/phscale/