1 26 unit #6 exam review

Launch: 1/26   Grab your binder and immediately take a seat!

  Place launch paper and yesterday’s practice questions on your desk.

  Yesterday’s Exit Slip Data:

  Today’s Objective: Review!

95%!

Launch: 1/26   Grab your binder and immediately take a seat!

  Place launch paper and yesterday’s practice questions on your desk.

  Yesterday’s Exit Slip Data:

  Today’s Objective: Review!

93%!

Launch: 1/26   Grab your binder and immediately take a seat!

  Place launch paper and yesterday’s practice questions on your desk.

  Yesterday’s Exit Slip Data:

  Today’s Objective: Review!

99%!

Launch: 1/26   Grab your binder and immediately take a seat!

  Place launch paper and yesterday’s practice questions on your desk.

  Yesterday’s Exit Slip Data:

  Today’s Objective: Review!

N/A

Launch 1/25

1.  pH is a measure of a.  the taste of an acid or a base. b.  the ability of a solute to dissolve in solution.

c.  the concentration of H+ ions in solution. d.  the strength of an ion in solution.

Launch 1/26 3.  Of the four different laboratory solutions below,

the solution with the highest acidity has a pH of a.  11. b.  7. c.  5.

d.  3.

Launch 1/26 5.  How many times more

acidic is stomach acid than rainwater?

a.  4

b.  10000 c.  40000

d.  100000

Announcements   Unit #6 Exam on Thursday!

  No notecard!   Ask questions

  Work with purpose

  2 review days   Today is super important – study guide

  Double points!

  Tomorrow jeopardy

  Class rules I am focusing on this week:   interfering with your own or someone else’s learning

  leaving seat without permission

January Calendar

Exam

Unit #6 Review Mr. Heffner 1/26/10

Review: Solutes vs. Solvent   A solution is a homogeneous mixture made up of a…

Solute   is dissolved   solid (or gas)

  molecules don’t move   Example:

Solvent   does the dissolving   liquid

  molecules randomly collide   Example:

more

Review: How are solutes dissolved?   The dissolving process:

1.  The solvent randomly collides with solute 2.  The solvent overcomes the attraction between solute

3.  The solvent surrounds the solute

Review: What is solubility?   Solubility is..

  how well a solute dissolves in a solution.

  Factors that affect solubility of solids 1.  Temperature: temperature = solubility 2.  Surface Area: surface area = solubility

  Factors that affect solubility of gases 1.  Temperature: temperature = solubility 2.  Pressure: pressure = solubility

more SA less SA

opposite!

Review: Concentration Calculations   Concentration is…

  the amount of solute in a solution.   g/L, mol/L (M), or ppm

  There is a 3 step process for calculating concentration: 1.  Look at the ending unit 2.  Decide whether to multiply or divide

  mol/L (molarity) or g/L divide

  moles or grams multiply

3.  Cancel units and do the math!

How many…? or

What is…?

Examples 1.  If 50g of NaCl is dissolved in 1L of H2O, what is the

concentration of the solution in g/L?

50 g 1 L = 50 g/L

grams divided by liters

Examples 2.  How many moles of NaOH are needed to prepare 2.0 L of

a 2 M solution?

2 mol 1 L = 4 mol 2 L x 2 X 2 mol

1 =

2 M = 2 mol/L

Examples 3.  A solution of salt water contains 15 grams of salt per

1,000 grams of water. What is the concentration in parts per million (ppm)?

15 1000 = ?

1000000

15 1000 = 15

1000000 000

15,000ppm

Review: What are acids and bases?   Solutions can be classified as…

Acids   pH < 7   taste sour

  burn skin   turn litmus paper red   donate H+ ions

Bases   pH > 7   taste bitter

  feel slippery   turn litmus paper blue   accept H+ ions

“pH scale”

Example 4.  In the below chemical equation, identify the

reactant that acts like an acid and the reactant that acts like a base.

  HF gives away an H+ (donates) = acid

  H2O takes an H+ (accepts) = base

HF + H2O F- + H3O+

gives away an

H+

turns into takes an H+

turns into

Strong acids/bases

  fully dissociate

Review: Strong vs. Weak

HCl H+ H+

H+ H+ H+

H+ H+ Cl-

Cl-

Cl-

Cl-

Cl-

Cl-

HCl H+ + Cl–

Weak acids/bases

  partially dissociate

HF H+ + F–

HF

HF H+

HF HF H+

H+ HF F-

F-

F-

F-

F-

F-

strong acids and bases neutralize each other H2O + a salt

Review Worksheet   Practice question worksheet

Homework   Finish practice questions