Transcript 01_24_25 - Alliance Ouchi-O`Donovan 6

Acids and Bases 5
Boon Chemistry January 24 & 25, 2013
Catalyst
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Take out your homework
please.
Think back to the
investigations you completed this
week. When a person takes Tums
(or another antacid) what happens
to the pH in their stomach? Why?
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Objectives
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I can demonstrate my knowledge of
acid/base chemistry on the Unit 7
exam.
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Agenda
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Catalyst and Homework
Review
Unit 7 Exam
Flashcards: Thermochemistry
Exit Slip: Answers Standard IE 1e/5d
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What is the [H3O+] in a 0.0040 M solution of NaOH (a strong
base)?
(a) 2.5 x 10-2 M
(c) 4.0 x 10-12 M
(b) 2.5 x 10-12 M
(d) 1.0 x 10-7 M
Why? 1.0 x 10-14 = [H3O+] (4.0 x 10-3) Solve by dividing.
As the [H3O+] of a solution increases, the value of
(a) log [H3O+] increases .(c) the solution’s pH decreases.
(b) –log[H3O+] decreases. (d) all of the above
Why? Test each answer. They are all true.
What is the [OH-] in a sample of lime juice with a pH of 2.0?
(a) 1.0 x 10-2 M
(c) 1.0 x 10-10 M
(b) 1.0 x 10-7 M
(d) 1.0 x 10-12 M
Why? Read carefully. If pH is 2, then pOH is 12. This
corresponds to 1.0 x 10-12 M
Exit Slip answers continued
(4) If the pH of a solution is increased from 2.0 to 4.0, the [H3O+]
concentration
(a) decreases by a factor of 2.
(b) decreases by a factor of 100.
(c) increases by a factor of 3.
(d) increases by a factor of 1000.
Why? As pH goes up, [H3O+] goes down. Each time you move one
space on the pH scale you are changing the [H3O+] by a factor of 10.
Moving 2 spaces is 10x10=100.
(5) What is the pH of household ammonia in which the [H3O+] is 1.0
x 10-12 M?
(a) 2
(c) 10
(b) 7
(d) 12
Why? 10-12 corresponds to pH=12. pH = -log[H3O+]
Homework Review page 544 1-4, 545 1-4
[H3O+] = 5.0 x 10-3 M pH = -log[H3O+]
pH = -log[5.0 x 10-3 ]
pH = 2.3
2. [H3O+] = 0.2 M pH = -log[H3O+]
pH = -log[2.0 x 10-1]
pH = 0.70
3. [OH-] = 2.0 x 10-3 pOH = -log[OH-]
pOH = -log[2.0 x 10-3 ]
pOH = 2.7 pOH + pH = 14; pH = 11.3
4. [OH-] = 0.35 M pOH = -log[0.35]
pOH = 0.45
pOH + pH = 14
pH = 13.55
1.
Homework Review page 544 1-4, 545 1-4
1.
pH = 3.3 [H3O+] = 10-pH
[H3O+] = 10-3.3
[H3O+] = 5.0 x 10-4
pH = 11.7; pOH = 14 - 11.7 = 2.3
[OH-] = 10-pOH = 10-2.3 = 5.0 x 10-3
3. pH = 8.1; pOH = 14 - 8.1 = 5.9
[H3O+] = 10-8.1 = 7.9 x 10-9
[OH-] = 10-5.9 = 1.3 x 10-6
4. pH = 7.67; pOH = 14-7.67 = 6.33
[OH-] = 10-6.33 = 4.7 x 10-7 This is outside the normal range,
the patient should be concerned.
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Acid/Base Exam
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Expectations/Instructions:
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The Tools:
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Work independently and silently.
Write on your test.
Be sure to answer every question. There are multiple choice
and short answer.
Use your pH foldable worksheet.
Use your own calculator.
If you finish early:
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Turn in your test and all your pH worksheets, handouts, etc.
Begin the flashcard assignment for Unit 8.
Thermochemistry Flashcards
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Front of card:
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Back of card:
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Vocabulary word
Picture/diagram
definition
Sentence using the word
Resources:
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Textbook Glossary
Words are also posted on
the wall.
Words
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Endothermic
Exothermic
Melting point
Boiling point
Freezing point
Condensation
Fusion
vaporization
Sublimation
Evaporation
Heat
Temperature
Energy
Enthalpy
Entropy
Joule
Specific heat
calorie
Homework
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Due Next Class: Complete your flashcards