1 / 9

Acids and Bases 5

Acids and Bases 5. Boon Chemistry January 24 & 25, 2013. Catalyst. 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?. Objectives

inari
Download Presentation

Acids and Bases 5

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Acids and Bases 5 Boon Chemistry January 24 & 25, 2013

  2. Catalyst • 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? • Objectives • I can demonstrate my knowledge of acid/base chemistry on the Unit 7 exam. • Agenda • Catalyst andHomework Review • Unit 7 Exam • Flashcards: Thermochemistry

  3. Exit Slip: Answers Standard IE 1e/5d • 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

  4. 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+]

  5. 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 • [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

  6. Homework Review page 544 1-4, 545 1-4 • 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 • 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.

  7. Acid/Base Exam • Expectations/Instructions: • Work independently and silently. • Write on your test. • Be sure to answer every question. There are multiple choice and short answer. • The Tools: • Use your pH foldable worksheet. • Use your own calculator. • If you finish early: • Turn in your test and all your pH worksheets, handouts, etc. • Begin the flashcard assignment for Unit 8.

  8. Thermochemistry Flashcards • Words • Endothermic • Exothermic • Melting point • Boiling point • Freezing point • Condensation • Fusion • vaporization • Sublimation • Evaporation • Heat • Temperature • Energy • Enthalpy • Entropy • Joule • Specific heat • calorie • Front of card: • Vocabulary word • Picture/diagram • Back of card: • definition • Sentence using the word • Resources: • Textbook Glossary • Words are also posted on the wall.

  9. Homework • Due Next Class: Complete your flashcards

More Related