Study Guide for Test 11/14

Chapter 12

Answers to Chpt 12 practice pg. 439
1. C
2. D
3. B
4. C
5. D
6. A
7. B
8. C
9. a. tetrahedral   b. trigonal planar   c. trigonal pyramid

What to study for Chpt 12
--types of bonds: what is difference between ionic, covalent an polar covalent
--what are the properties of an ionic bond
--understand what is electronegativity and what elements have the highest/lowest electronegativity
--what is a dipole moment in a molecule and be able to tell what is the positive and negative side of the bond
--know what are the charges that elements in groups 1-8 make when they form an ion
--know what will be the formula when two elements form a compound by their ionic charges
--know how to make Lewis structures for covalent compounds
--know that all atoms (except hydrogen and helium) are looking for eight electrons due to the octet rule
--know how to recognize a lone pair and a bonded pair of electrons in a Lewis structure
--know what VSEPR model or shape that the molecule will take based on its Lewis structure

Chapter 7:

Practice test pg. 237
1. D
2. B
3. C
4. D
5. A
6. B
7. C

9. Mg (s) + 2H₂O (l)   arrow         H₂ (g) + Mg(OH)₂ (aq)

10. Pb(NO₃)₂ (aq) + 2NaI (aq) arrow  PbI₂ (s) + 2NaNO₃ (aq)

11. C₃H₈ (g) + 5O₂  arrow   3CO₂ (g) + 4H₂O (g)

12. 2Ca(s) + O₂ (g)   arrow   2CaO (s)

 
--know what are the signs of a chemical reaction
--what makes a reaction chemical as opposed to physical
--how to make formulas for a chemical equation
     --keep in mind roman numerals for transition metals
     --remember that gases and halogen elements are always diatomic and have two atoms

Identification of chemical reactions lab

Make sure to finish the three questions for the lab and identify the mystery solution by name.

3. What is the identity of the unknown solution?:

4. What signs of a chemical reaction did you observe?

5. Balance the following chemical reactions from your experiments:

NaOH + HCl                       H₂O + NaCl

CaCl₂ + NaOH                    Ca(OH)₂ + NaCl

Homework for 11/10

1) pg. 234-5 #5-8, 31-36
2) All Chapter 12 homework due by Monday!
3) Tutoring after school Wednesday!
4) Homework drop in Monday & Wednesday next week.

Homework for 11/6

1) Read Chapter 7
2) pg. 219 #1-3, pg. 234 #2-4

Tutoring Friday & next Wednesday

Homework for 11/4

1) pg. 437-8 #44, 47-48, 54, 56-59
2) Tutoring on Wednesday & Friday-chpt 4 & 11

Dry Ice Lab

Dry Ice Lab

Preparation Questions:

1. Taste the apple juice.  How does it taste, be descriptive.

2. Measure the temperature of the rubbing alcohol before the dry ice is put in.

Observe dry ice:

3. What happens when dry ice is left on your table?

4. How is it different than regular ice?

5. Place a metal object on the dry ice what happens?

6. What happens when dry ice is placed in cup with plastic wrap on top?

7. Pour the dry ice vapor over the lit candle.  What happens to the candle?  Explain why this happens.

Dry ice in water:

8. What happens when dry ice is placed in warm water?

9. Is the water boiling?  Why are there bubbles going up the cup?

10. When “steam” comes out of the beaker, it goes down instead of up like steam from a pot of boiling water.  Why do you think this happens? (Hint: think about what you know about density!)

11. Observe the dry ice after it has been in the water for a longer period of time.  What happens to the bubbles and the dry ice?

Dry ice in soapy water:

12. Feel the bubbles from the dry ice in soapy water.  How do they feel different from regular bubbles?

13. What happens when you pop the bubbles?

Apple juice & dry ice:

14. Drink the apple juice after the dry ice has become gas.  Does it taste any different?

15. Does it remind you of anything else that you drink? Compare it to other beverages.

Dry ice & rubbing alcohol:

16. Measure the temperature after the dry ice is put in the beaker.

17. Carefully place a leaf or flower into the beaker.  After a minute, ask Ms. Cotta to take it out.  What happened to the plant? Be very descriptive.

18. Why did this happen to the plant?

Questions:

19. What is it called when a substance such as dry ice goes from solid directly to a gas?

20. How is dry ice different from water ice?  How is the temperature different? Water freezes at 0 degrees Celsius.

21. Did the dry ice float or sink in the water?  Why would it do this explain and compare it to water ice.

Homework for 11/3

pg. 429 ex 12.6 a-e, pg. 433 a-d, pg. 437 #39-42