acids and bases day 5.2012

Today in Chemistry

You will Need:1)Pencil, Colored Pencil2)Acids and Bases Parts 1 & 2 Should already have 4 pages 7 sides – Please staple3)Test #3 Corrections & Student Self Assessment – Due Tomorrow up last week)

Test #3 RetakesTest Corrections + Student Assessment – Due Tomorrow.•Retakes offered Friday at Lunch, •Monday, April 30th before school and at lunch•Tuesday, May 1st before school and at lunch

Quiz #4 – Review & Reflect

Look over the questions you missed on Quiz #4– Why did you miss them?•Ask a table mate to clarify•Did you misread the question?•Where your mistakes careless?•Do you need to review the concept, vocabulary word, formula, etc.?

STAR SCIENCE COMPONENT tomorrow

ACID BASE

ION: A positively or negatively charged atom/molecule

7

NEUTRAL 0-6.9 7.1-14

pH Scale:

Measures the # of H+ ions in a solution (Potential Hydrogen Ions)

1. Shade the center area of your data table with the appropriate color.

Acid Base

Both

Word Bank:

base, pH, salt, acid,

neutralpH

1. Timer Designers – Log – on to Learning Point and open up – ACID and BASE Virtual Lab

2. Turn to #6 Interactive Computer Activity

Bromothymol Blue in the presence of ACID, NEUTRAL and BASE

Visit the Explore the pH Factor option on the class

website:

1.One of the pH paper colors is wrong.

2.Which one?

3.Why?

4.Highlight the wrong row with a colored pencil. http://www.miamisci.org/ph/

8. Bleach has a pH of about 13. If you mix a solution of 50% bleach and 50% water, what would be true about the pH of a the mixture?

A.It would be less than 7B.It would be between 7 and 13C. It would be greater than 13D. There is not enough info to solve

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Water Bleach

13 More OH-

7Neutral

H2O Some of the Negative OH- particles will diluted by the Neutral particles of the water.

9.Suppose you have already compared the pH values of two substance using 0-14 pH paper. When would a follow-up test using 4.5-7.5 paper be most helpful?

A.When both sub. had a pH value of about 3 on the 0-14 paper

B.When both sub. had a pH value of about 6 on the 0-14 paper

C.When both sub. had a pH value of about 9 on the 0-14 paper

D.When on substance had a pH value of about 5 and the other had a pH value about 7 on the 0-14 paper.

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A B C

D

Which choice not only fits the requirements of the new testing paper (4.5-7.5) but also needs to show a difference between two solutions?

Retest the solutions that both have a “6” as an answer to show how they are different.

New testing strip range

10. Suppose you had needed to neutralize a strong acid (pH2). Describe 2 ways you could do this safely.

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Vinegar Equal strength Alkaline

Substance

Lots of Water

Lots of H+

Lots of OH-

Caution: You wouldn’t want to mix a strong acid with a strong base…. You would get a VERY exothermic reaction, meaning that you now have a VERY HOT mixture of strong acid and base.

10. Suppose you had needed to neutralize a strong acid (pH2). Describe 2 ways you could do this safely.

11. Explain how OH- values and H+ values determine Acids and Bases.

10. Suppose you had needed to neutralize a strong acid (pH2). Describe 2 ways you could do this safely.

11. Explain how OH- values and H+ values determine Acids and Bases.

12. Why is it important to be careful with the things that we put down the drain or that we let evaporate into our air? (3-4 sent.)

1.Work on Acids and Bases Parts 1 & 2 questions

#22 – has two answers#25 (NH4)2SO4

#24 “C” is listed twice – 2nd one should be a “D ”

1. Periods 1,3,5,6,8 – Acids & Bases due Friday

2. Period 2 – Acids & Bases due Monday – Apr. 30

3. Test # 3 corrections and self assess.- Due Tomorrow.