Acids Acids and and

BasesBases

Understanding Acids and Understanding Acids and BasesBases

7.5-8

Baking Soda 8.5 - 9

Lemon Juice 2.5-3

Normal Rain 5.6-6.5

Drain Cleaner (NaOH)

12 - 14

Battery Acid .5-1

Stomach Acid .5-1

Milk 6.5

Ammonia 11-12

Orange Juice 3.5

Cola 2.5-4

SalivaDistilled Water

Tap Water

Vinegar

7 - ish

2.5-3

6 -7.4

Putting it all TogetherPutting it all Together

Characteristics of AcidsCharacteristics of Acids

Taste sourTaste sour

pH less than 7pH less than 7

Corrode MetalCorrode Metal

Conduct electricity very wellConduct electricity very well

Characteristics of BasesCharacteristics of Bases

pH greater than 7pH greater than 7

Taste bitterTaste bitter

Good CleanersGood Cleaners

Feel slipperyFeel slippery

Understanding the pH Scale

0 7 14Acidic Basic

Neutral

•The pH scale is a logrithmic scale.

•A difference of one pH unit represents a tenfold change

•A difference of 2 pH units, for example from 6 to 4, would mean that the acidity one hundred times greater.

Check Your Understanding

How many times more acidic is a tomato than coffee?

How many times more acidic is tomato than saliva?

How many times more acidic is lemon juice than coffee?

10

100

1,000