acids, bases, & their solutions the ph scale is a substance an acid or a base?
TRANSCRIPT
ACIDS, BASES, & THEIR
SOLUTIONS
The pH Scale
Is a substance an acid or a base?
ACIDS• a compound that increases the
number of hydrogen ions (H+) when dissolved in water
• tastes sour• An acid can change the color of
certain compounds
What is an ion?
An ion is an atom that has lost or gained an electron giving it a positive (+) or
negative (-) charge.
USES OF ACIDS• Citric & ascorbic acid (Vitamin C) =
orange juice• Carbonic & phosphoric acid give a “bite”
to soft drinks• Acids in your stomach aid in digestion• Sulfuric acid is the most widely used
industrial acid in the world. It’s used in making metals, paper, paints, and fertilizers.
BASES• any compound that increases the
number of hydroxide ions (OH-) when mixed with water
• tastes bitter• feel slippery• A base can change the color of certain
compounds
Uses of Bases• used in soaps (remember, bases
are slippery)• used to make paper, in oven
cleaners, and to unclog drains• Ammonia is a base and is used in
many household cleaners
Detecting Acids and Bases
• You can detect an acid or a base using an indicator.
• INDICATOR - A substance that changes color in the presence of an acid or a base.
INDICATORS• Litmus paper is an indicator
An acid turns blue litmus paper redA base turns red litmus paper blue
• Cabbage juice can be used as an indicator.• pH paper- turns a color & then match it to
the pH scale given.• pH meter- will give you a number for the
solution.
HOW DO WE MEASURE pH & WHAT IS pH?
pH= stands for powers of Hydrogen.
---It’s a measure of the hydronium ion
concentration in a solution.
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14
ACID BASE
NEUTRAL
The pH Scale
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14
ACID BASE
NEUTRAL
The pH Scale
Let’s see what you’ve learned!Mrs. Borras wants to
know what you’ve learned. Answer the following questions carefully.
DO NOT ANSWER OUT LOUD!!!!! Write it down.
Question #1
• Lemon juice has a pH of 2.2. Is it an acid or a base?
Question #2• Detergents
such as Tide have a pH of about 10. Is Tide an acid or a base?
Question #3• Seawater has
a pH of 8.2. Is seawater an acid or a base?
Question #4• The inside of
your mouth has a pH of 7. Is it an acid or a base?
Question #5• How do you
think we came up with the term “acid rain”?
Question #6• 409 cleaner
contains ammonia that has a pH of 12. What will 409 do to red litmus paper?
Question #7• A soft drink
has a pH of 3.2. What will it do to a piece of red litmus paper?
You’ve just completed Mrs.
Borras’ Quiz
Let’s see how you did!