Monday, December 15, 2008

New Day: New Task...

Last time we learned about hydrothermal vents...the physical and chemical properties surrounding the vents....and how energy is transfered throughout these unique environments. Today we are going to learn more about the chemical properties of hydrothermal vents.

To start with...Figure out the oxidation numbers (number of electrons in the outer shell) of Zn, Fe, and Cd using the following chemical equations:

ZnCl2
FeCl3
CdCl2

Making Smoke...

Now that we know the oxidation numbers for the metals Zn, Fe, and Cd we can predict how they will react with Hydrogen Sulfide (H2S). Give it a shot...React ZnCl2, FeCl3, and CdCl2 with H2S.

Hint 1: What is the oxidation number of H?

Hint 2: What is the oxidation number of S?

Your final Hint: The charge needs to be balanced.

Being a Geochemist

Here is your challenge...You will be given a vial with an unknown substance (either Zn, Fe or Cd) and you have to tell us what it is. To do this we have to learn about the chemical properties of each metal.

Each group take three vials.

Fill ONE vial 1/2 full with ZnCl2.

Fill ONE vial 1/2 full with FeCl3.

Fill One vial 1/2 full with CdCl2.

(be sure to label your vials so that you know which is which)

Now add 5 drops of Na2S to each of the 1/2 Full vials and record what happens.

Into the Unknown

Now that you have learned about the chemical properties of Zn, Fe, and Cd when they react with Na2S, use this piece of knowledge to figure out what unknown we gave you.

Hint: Do an experiment.

Tuesday, December 9, 2008

Step 1: The Basics...

Hydrothermal vents? What are they and where do you find them? That is your first task! You and your partner need to describe (in YOUR own words) what a hydrothermal vent is and where you would look to find one. Get to it! You have 10 min...GO!

Step 2: Physical Properties

Now lets get down to business! You remember way back when we learned about Physical properties...Well, now it's time to dust off that piece of knowledge and use it. Your task is to tell us about the physical properties surrounding hydrothermal vents. What's it like inside the vent? How do the physical properties change as you move away from the vent?

By the way, you have 15 minutes!

Step 3: What is the SMOKE?

Now that you have covered physical properties, the next thing to do is to describe the chemical properties. Describe the chemical environment (chemical properties) near hydrothermal vents. What reactions are taking place inside hydrothermal vents? What is the smoke?

You guessed it...You hae 15 minutes.