Homework for 10/30

1) HW drop in W & F
2) pg. 433 #1-5, pg. 436-7 #30, 33-37
3) Tests due Friday

Missed Homework Post for 10/23

1) pg. 417 ex. 12.2, pg. 419 ex 12.3, pg. 421 ex 12.4 a thru i (all examples problems from the text)

Homework for 10/28

1) pg. 435 #14-18, 21, 25-29
2) makeup for test due Friday!

Ionic vs. Covalent Lab

Ionic vs. Covalent Compounds

Objective: To test various substances to determine whether they are composed of ionic bonds or covalent bonds by identifying their properties.

Procedure:

1.  Each partner in the group will test two different substances. Group A member will test sugar and unknown #1. Group B member will test salt and unknown #2. Group C member will test wax and unknown #3.

2. Conduct the same procedure for each sample. Take a spoonful of the substance in your small test tube and place it in the hot water bath. 

3. Leave it for three minutes in the hot water and write observations.

4. Add a spoonful to the large test tube and fill the test tube 1/3 full with water.

5. Then gently shake it up for a minute to see if dissolves or mixes with the water and write down observations.

6. Add a small amount of the sample mixed with water and add it to your testing tray.

7. Use the electric meter to test whether it will conduct electricity and write observations.

8. Repeat with the other compounds.

Pre-lab Questions:

1. Explain what makes an ionic bond by discussing what type of elements make it up and how it is able to create a bond.

2. Explain the same for a covalent bond.

3. What are the properties of an ionic compound? A covalent compound?

Observations:

	After heating:	Mix with water:	Conductivity:
Salt:
Sugar:
Wax:
Unknown #1:
Unknown #2:
Unknown #3:

Post-lab:

·        Decide whether the two compounds that you tested are covalent or ionic.

·        Discuss with your partners and share your observations with them. Group member A shares first, then B, then C.

·        Come to agreement about each compound with your partners and write down your results

Substance:                    Covalent or Ionic?        Reasoning:

Salt:

Sugar:

Wax:

Unknown #1:

Unknown #2:
Unknown #3:

1.Which do you think is a stronger bond, covalent or ionic, after your observations? Make sure to explain why, using evidence.

2. Define these compounds as covalent ionic based on their component elements:

a. MgS

b. CO

c. SO₂

d. LiCl

Homework for 10/27

1) pg. 422 #1-2, #4 (don’t do iii), pg. 435 #1-12
2) If you have not turned in composition book, please turn in.

Comparing Copper Chloride Lab

Comparing Copper (I) Chloride and Copper (II) Chloride

Objective: To observe and identify the difference between physical and chemical change of two substances. To identify and record the quantitative and qualitative properties of substances before and after a physical or chemical change of copper I, copper II and aluminum.

Pre-Lab Questions:

1. What is the difference between quantitative and qualitative observations?

2. Do you think that the CuCl and CuCl₂ will have the same properties? Why or why not?

Procedure:

1. Weigh 0.25 grams of CuCl powder (green) on electronic balance.

2. Weigh 0.50 grams of CuCl₂ (blue green) crystal on electronic balance.

3. Using a graduated cylinder, measure 50 mL of water, pour into beaker, do this twice once for each beaker.

4. Record the temperature of the water in each beaker.

5. Pour the CuCl into a small beaker.

6. Stir to dissolve all of the CuCl and record new temperature.

7. Pour the CuCl₂ into a big beaker.

8. Stir to dissolve all of the CuCl₂ and record new temperature.

9. Take a piece of aluminum foil and add it to each solution. Observe for a few minutes and record a second temperature.

10. While you are performing steps, record your observation of qualitative and quantitative observations.

Qualitative observations:

CuCl:                                                          CuCl₂:

1.                                                                1.

2.                                                                2.

3.                                                                3.

Quantitative observations:  

CuCl temperature:                                     CuCl₂ temperature:

H₂O Before:                                               H₂O Before:

Dissolving:                                                 Dissolving:

After aluminum:                                        After Al:

Post-lab Questions:

1. What are the charges for copper in CuCl and CuCl₂? What does this change in the formula for each of the compounds?

2. Which reaction had the greatest change in temperature? Was there a connection to which solution reacted more with aluminum and its temperature?

3. Identify any chemical changes in your experiment and explain why it is a chemical change. Make sure to explain your evidence why it is a chemical change.

Homework for 10/21

Homework due for Tuesday, October 21st!

1) HW Drop in M & W, NOT Friday
2) pg. 404 #a-d, pg. 406 #6, pg. 412 #4-6

Homework for 10/20

1) Read Chpt 12
2) pg. 406 #1-5, pg. 412 #1-3

Homework for 10/16

1) pg. 118 #3-4, 6, 8, 10-13, 17-19-21, 25-27
2) HW Drop in M, W & F-today
3) Chapter 11 & 4 Test Friday
4) Last day for all HW from Chpt 11 & 4 DUE FRIDAY!
5) Make sure all labs are completed in composition books, all lab questions are posted online!

Study guide for Chapter 11 & 4 Test

Here are the topics to know for the test for Chapter 11 & 4 that will be on Friday.

Chapter 11:

• what is electromagnetic radiation
• know the different types of electromagnetic radiation and what is the wavelength and amount of energy for the different types
• know what wavelength means in regards to a wave
• understand that light has a dual nature as both a wave and a packet of energy called a photon
• understand what occurs when an electron absorbs a photon and what occurs when the electron gives off the photon
• know the difference between ground state and excited state
• understand why there are different colors of photons that we observe when atoms are excited

• understand the difference between an orbit and a orbital
• know the 4 principal energy levels and the sublevels of s, p, d and f
• know how many electrons are held in each of the sublevels
• know how to determine the electron configuration (1s2 and so forth) of an atom
• know the shapes of s, p and d orbitals
•  

• know what a valence electron is and its role in determining an atom's properties
• know how atom size changes on the periodic table
• know how the ionization energy changes across a periodic table

Chapter 4:

• know how to name compounds in three different ways
• when the first element is a metal and the second element is a nonmetal
• when the first element is a transition metal and the second element is a nonmetal
• when both of the elements are nonmetals
• know how to name compounds that contain  polyatomic ions
• know how to determine the formula by knowing the name of the compound (reverse of knowing the formula!)

Homework for 10/14

Note that this homework is due on Tues. Oct. 14th not on Monday.

pg. 108 #1-6, pg. 111 #a-g, pg. 112 #a-f, pg. 115 #a-e

Spectroscopy Lab Questions

Spectroscopy Lab

Objective: To identify the elements shown via their emission spectrum using a spectrograph.  To use the spectrograph, hold the small slit to your eye and view the lighted gas tube directly through the viewfinder.  Then look to your left to view the emission spectrum for that element.  In your composition book make a drawing of the colors that you see and their approximate distance from each other.

Pre-Lab Questions:

1. How does an atom become excited? What happens when the electron returns to ground state?

2. How are we able to identify different elements from distant stars?

Spectroscopy drawings:

3. Element #1:

4. Element #2:

5. Element #3:

6. Element #4:

Element identification:

8. Identify the elements by looking at the emission spectrum samples at your table.

Element #1: _______________              Element #2: _______________

Element #3: _______________              Element #4: _______________

9. Examine the sample emission spectrum from a nebula (a cloud of gas that will become a star). Using your spectrums that you identified, determine what elements are found in the nebula.

Questions:

10. How is spectroscopy useful when examining a star or planet, especially when we are unable to actually visit it?

11. Look at the elements that were found in the nebula, then look at the periodic table. Are there any similarities about these elements?