Candium and pennium

PENNIUM LAB


OBJECTIVE
In this lab you will investigate the concept of atomic mass and how it was derived. You will develop your own unit of measure, te CMU, and use it to measure the relative mases of other coins. At the conclusion of this lab you will be able to explain how scientists developed the system for the AMU's (atomic mass units) and how it is applied to determine the relative masses of other atoms of other elements.


PROCEDURES
    PART 1
1) Obtain a packet of pennies.
2) Sort the pennies into two groups: pre 1982 and 1982 and newer.
3) Measure the mass (in grams) of each stack of pennies. Record the mass (in grams) of each penny stack in a data table. Count the number of pennies in each stack. 
4) Measure the mass in grams of a half dollar, quater, nickel, and dime. Record these values in a data table.
5) Answer the questions below and then continue with Part 2.


QUESTIONS
   PART 1
1) Does each penny have the same mass?
2) Can you identify two "penny isotopes" based on masses of the pennies? Explain.
3) What does your data tell you about the relationship between mass of a penny and date of a penny. Make a generalization.


PROCEDURES
   PART 2
1) Determine the average mass of pre-1982. (Record Average)
2) Determine the average mass of post-1982. (Record Average)
3) Determine the percentage of your pennies that is pre-1982 and the percentage that is post-1982. These percents should add up to 100%. What you have calculated is the percent abundance of each group of pennies (penny isotope).
4) Let's choose one of your coins to make a CMU (coin mass unit). Let's say that  the mass of a nickel (Fivecentium), quarter (Quarterium), dime (Dimeium), pre-82 pennies (Pre-82 Pennium), post-82 pennies (Post-82 Pennium). Again, show all calculations, and record all data in a data table.
5) Determine the average mass of Pennium in CMU's using the percent abundance (from #3) of each pennium isotope (pre-82 and post -82) and the mass of each pennium isotope in CMU's (from #4). 


QUESTIONS and CONCLUSIONS
   PART 2
1) Make a statement about the average penny mass of pre-82, post-82, and pennies in the packet.
2) Explain how you derived the unit "CMU".
3) Using the idea you explained in #2 above, how did scientists obtain the Atomic Mass Unit (AMU) to measure the ass of atoms of different elements?
4) What is your weight in CMU's? (Remember 1 lb = 2.205 Kg)
5) Write a statement that compares what you did in this lab to what scientists have done to find the average atomic masses of the elements. 

	Pre 1982	Post 1982	Nickel	Dime	Qaurter
Mass	2.5	3.04	5	2.3	5.7
Relative Abundance	11	14	1	1	1
Average Mass	.5g	.61g	1g	.46g	1.14g

CANDIUM LAB
Purpose
* To use a Candium model to explain the concept of atomic mass.
* To analyze the isotopes of Candium and calculate its atomic mass.


Materials
~ Sample of Candium
~Balance


Procedure
1. Obtain sample of Candium.
2. Separate it into its 4 isotopes. (M&M's, Skittles, Sixlets, Gobstoppers)
3. Determine the total mass for each isotope.
4. Count the numbers of each isotope.
5. Recorde data and calculations in the data table creat a data table that has the following:
   1. Average mass of each isotope.
   2. Percent abundance of each isotope.
   3. Relative abundance of each isotope
   4. Relative mass of each isotope
   5. Average mass of all isotopes
Your data table should have five columns and seven rows.


Discussion 
1. Summarize what you did.
2. Define the term isotope.
   Isotope- One of two or more atoms with the same atomic number that contain different numbers of neutrons. 
3. Explain the difference between percent abundance and relative abundance. 
   (Hint: What is the result when you total the individual percent abundance values for each isotope?
             What is the result when you total the individual relative abundance values for each isotope?)
4. Compare the total values for rows 3 and 6 in the data table. How does the average mass differ from the relative mass?
5. Compare your value for  relative mass to that of the class.
6. Comment on your percent error in the activity, and provide suggestions for improvement.
7. Comment on how the activity is a model for calculating atomic mass of real elements.


Conclusion:- 
  

Candy	Gobstoppers	M&M's	Skittles	Sixlets
Average Mass of Each	1.67	.87	1.08	.81
% Abundance	.19	.26	.21	.32
Relative Abundance	9	12	10	15
Relative Mass of Each	2.06	1.07	1.33	1
Average Mass of All	1.11	1.11	1.11	1.11

Intro to Chemistry Lab

Purpose:

        To become familiar with the laboratory and to make qualitative and quantitative observations about physical and chemical changes during a chemical reaction.

Materials:

Beaker

Copper(II) sulfate pentahydrate - caution, toxic substance

Scoopula

100ml graduated cylinder

Stirring rod

Thermometer

Small Square of Aluminum Foil

Procedure:

        This lab is unique in that it serves both as an introduction to both the laboratory environment and as a review and demonstration of terms and concepts we have recently learned in lecture. Thus, as you read and follow the procedure, be sure to answer all questions that are posed to you in the space provided.

        First, form a lab group of two or three people. Go to your lab station after taking all appropriate safety precautions we have discussed in the safety lecture. (You MUST wear safety goggles and apron)

        You will find in front of you a beaker (150 or 250 ml), a 100 ml graduated cylinder, a scoopula, a thermometer, some aluminum foil, and a container holding some cupric sulfate pentahydrate. Go to the appropriate source and add some water in your beaker. The exact amount is not important, although it should be between 75 and 100 ml.

        Make one qualitative and two quantitative observations of a physical property of the water. Be sure to distinguish which is which.

        Now, using the scoopula, obtain some of the copper(II) sulfate pentahydrate. Again the exact amount is unimportant, but your scoopula should be about one quarter filled with the solid (ask if you have any questions). Place the CuSO45H2O in the beaker, and stir with the stirring rod until all the solid has dissolved.

        Obtain the aluminum foil sample in front of you and crumple it into a loose ball. Place the aluminum ball into the copper(II) sulfate solution, and stir gently for about 15 sec. 

        Write down detailed observations of everything you see. One of them should be a quantitative.
        Make sure your scoopula is clean (rinse with tap water and dry with a paper towel if not) and obtain a large scoop of sodium chloride from the labeled container. Add the NaCl to the beaker containing the copper(H) sulfate - aluminum mixture. Stir until all of the sodium chloride is dissolved.

        Write down detailed observations. At least one needs to be a quantitative.

        After approximately 10 minutes, take your beaker over to the large funnel and beaker and slowly decant (pour) your mixture into the beaker. The instructor will show you a way to do this that will insure that all the liquid ends up in the funnel. Then clean your beaker thoroughly with soap and tap water, and then final rinse with distilled water. Make sure your lab station is clean, return all safety equipment to its proper location, and return to your desk.

Hypothesis:
        We hypothesized that the mixture would eat away the aluminum foil.

Data:
        Nothing happened until you add the NaCl to your mixture and it begins to rust away the aluminum tin foil until it rusts to nothing but rust.

Lab Discussion:

        Did a chemical change occur after the addition of the aluminum? Explain.

        Did you just see a physical change or a chemical change? Explain.

        How many different states of matter do you observe? Describe, from your observations, what they are. Which do you see in the beaker right now?

        Any idea what the red solid is that has dropped to the bottom of the beaker?

        You have just observed a chemical reaction between copper ion and aluminum, which produced copper metal, hydrogen gas, and aluminum ions. During the course of the reaction, you should have made several different observations that are all indicators that a chemical change is occurring.

Conclusion:
        Our hypothesis was that the mixture would eat away the aluminum foil. It did but it turned into rust. Creating a new substance making a chemical change.

Indicators of Chemical Change

1. Formation of a Participate
2. Heat Transfer 
3. Color Change
4. Bubbles without heat