1. Indicators
Tuesday, November 11th, 2014

2. Do Now HW
Thursday we will have a chance to retake the test
I put the test online so you can look at the questions that you got wrong
Do Now
Write down what you remember from the last VSVS lesson about acids and bases.

3. Objectives SWBAT describe the pH scale.
SWBAT identify how indicators are used to identify the pH of acids and bases.
Essential Questions
What is the pH scale? How are indicators used to measure acids and bases?

4. Essential Vocabulary pH Indicator
A measurement of how acidic or how basic a substance is.
Indicator
A substance that tells us if a substance is an acid or a base

5. More about pH It is a logarithmic scale Ratio of H+ to OH- ions
A substance with a pH of 3 is 10 times more concentrated than a substance with a pH of 4
Ratio of H+ to OH- ions
Distilled water has a pH of 7
H+ equals OH- ions
Acids have a pH less than 7
More H+ ions
Bases have a pH greater than 7
More OH- ions

7. Who wants to see a magic trick?
Indicators

8. Litmus paper Blue Red Acid Turns red No change Base Turns blue
“Base to Blue”

9. Answer the Essential Questions
What is the pH scale? How are indicators used to measure acids and bases?

10. Exit Ticket What is the pH of an acid? What is the pH of a base?
What is the pH of distilled water?
What will happen if you…
Put blue litmus paper in an acid?
Put blue litmus paper in a base?
Put red litmus paper in an acid?
Put red litmus paper in a base?