Loading presentation...

Present Remotely

Send the link below via email or IM

Copy

Present to your audience

Start remote presentation

  • Invited audience members will follow you as you navigate and present
  • People invited to a presentation do not need a Prezi account
  • This link expires 10 minutes after you close the presentation
  • A maximum of 30 users can follow your presentation
  • Learn more about this feature in our knowledge base article

Do you really want to delete this prezi?

Neither you, nor the coeditors you shared it with will be able to recover it again.

DeleteCancel

Make your likes visible on Facebook?

Connect your Facebook account to Prezi and let your likes appear on your timeline.
You can change this under Settings & Account at any time.

No, thanks

Untitled Prezi

No description
by

Christine Tran

on 13 June 2013

Comments (0)

Please log in to add your comment.

Report abuse

Transcript of Untitled Prezi

COLLLECT AND TEST OXYGEN/HYDROGEN GAS MIXTURES
WHAT ARE WE GOING TO DO?
INTRODUCTION
MATERIALS
WHAT DO WE NEED?
Avoid contact of ALL chemicals with skin and eyes
Notify your teacher immediately in the case of a spill.
Wear chemical splash goggles and chemical resistant gloves and apron
Wash hands thoroughly with soap and water before leaving the lab
Tie your hair back
Roll up sleeves
SAFETY PRECAUTIONS
Julie Truong, Christine Tran, Anh Nguyen, and Lilian Phan
MICRO MOLE ROCKETS
The combustion reaction of hydrogen and oxygen produces an explosive energy that can power a rocket.
We're going to generate micro scale quantities of hydrogen and oxygen and test their explosive nature separately, then in mixtures of different ratios.
Our goal is to find the most explosive gas mixture to launch a successful rocket.
CONCEPTS
WHAT CONCEPTS DO WE USE?
BACKGROUND
ABOUT HYDROGEN AND OXYGEN
Hydrogen is a colorless, odorless gas that is combustible. It is the most abundant element in the universe. In this lab, it is generated by the reaction of zinc with hydrochloric acid.

Oxygen is also a colorless, odorless gas. Combustible materials need oxygen in order to burn. It is the most abundant element on Earth. Oxygen is generated by the decomposition of hydrogen peroxide, but it needs a catalyst to start the reaction.
- We will use yeast to catalyze the decomposition of hydrogen peroxide to generate the oxygen gas.
EXPERIMENT OVERVIEW
WHAT IS THE PURPOSE OF THIS EXPERIMENT?
Our goal is to generate hydrogen and oxygen and determine the best, most successful ratio for their combustion reaction. We will use stoichiometry and mole ratio in order to find the best mixture of hydrogen and oxygen to propel the rocket

This ratio will be used to calculate the mole ratio for the reaction of hydrogen and oxygen in a balanced chemical equation.

The concept of limiting reactants will explain the results from different hydrogen/oxygen ratio mixtures.
PRE-LAB #1
Zn (s) + 2 HCl (aq) ZnCl (aq) + H (g)
2
2
What is the total amount of hydrogen gas that can be produced in grams with 5.00 grams of zinc?
5.00g Zn
1 mol Zn
65.38g Zn
1 mol H
2
1 mol Zn
2.02g H
2
1 mol H
2
0.154g H
2
PRE-LAB #2
2 H O (aq) 2 H O (l) + O (g)
2
2
What is the total amount of oxygen gas that will be produced in grams if you started with 15 grams of hydrogen peroxide?
2
7.1g O
2
2
2
yeast enzyme
15g H O
1 mol H O
2
34.02g H O
2
2
2
2
2 mol H O
2
2
1 mol O
2
1 mol O
2
32.00g O
2
Write the balanced chemical equation for the single-replacement reaction of zinc and hydrochloric acid to generate hydrogen gas.
Write the balanced equation for the yeast-catalyzed decomposition of hydrogen peroxide to generate oxygen and water.
3 M, 15 mL hydrochloric acid, HCl
15 mL 3% hydrogen peroxide, H O
5 mL 2% yeast suspension
5g mossy Zinc, Zn
10mL graduated cylinder
2 one-hole rubber stoppers
test tube rack
2 small test tubes
Beral-type pipets, graduated
1 match/lighter
Each gas generator consists of a small test tube, a rubber stopper, a gas delivery tube, and a gas collection bulb


1. Cut four Beral-type pipets to make four gas-collecting bulbs and four gas-delivery tubes. Discard the middle part of the pipet stem. Make sure the lengths are similar.

2. Place the gas delivery tube ends into the tops of rubber stoppers.

3. Prepare a hydrogen gas generator by placing about four pieces of mossy zinc into the bottom of a small test tube marked "HCl".

4. Prepare an oxygen gas generator by placing about 2 mL of yeast suspension into the bottom of the other small test tube marked "H O".

5. Set the test tubes in a test tube rack.
PROCEDURES...
CONSTRUCT GAS GENERATORS
6. Fill a 250 mL beaker about 1/2 full with water.

7. Immerse one of the cut-off pipet bulbs under water to fill it up.

8. Squeeze the water out of the pipet bulb into an empty graduated cylinder to measure the total volume of water in the bulb.

9. Refill the pipet bulb, then squeeze out 1/6 of the total volume into an empty graduated cylinder.
Release the squeeze and use a permanent pen to mark the water level on the side of the bulb.

10. Squeeze out a second 1/6 volume, mark the level again, and repeat for the remainder of the water.
This would divide the bulb into 6, equal-volume increments.

11. Copy the rest to save time.
CALIBRATE GAS COLLECTION BULBS
COLLECT AND TEST HYDROGEN AND OXYGEN GASES
12. Add 3 M hydrochloric acid to the mossy zinc until the liquid level is about 1 cm below the mouth of the test tube. Cap the tube with the gas delivery stopper. Wait 1 minute for the air to be purged from the test tube.

13. Completely fill a marked pipet bulb with water and put it over the gas delivery tube to collect the gas by water displacement. As the bubbles enter the pipet bulb, the water will flow out of the bulb and down the sides of the test tube.

14. Once the bulb is filled with hydrogen, remove it from the gas delivery tube and place a finger over the mouth of the bulb to prevent the collected gas from leaking out.

15. Hold the gas bulb so the opening is pointed upward and have a classmate quickly strike a match over the opening. Let the hydrogen escape into the flame. Record the results of this "pop test" in the data table.

16. Add 3% hydrogen peroxide to the yeast suspension until the liquid level is about 1 cm below the mouth of the test tube. Cap the tube with the gas delivery stopper. Wait 1 minute.

17. Repeat steps 13-15 to collect oxygen gas and test its properties. Record the results of its "pop-test" in the data table.


25. Collect the optimum (loudest) gas mixture one more time, and bring it to the teacher. The teacher will place the bulb on a rocket launch and ignite it with a piezo sparker. See how far it travels.

26. Collect the optimum mixture again, but this time leave about 1ml of water in the bulb. With the teacher's consent, launch the micro mole rocket.
H
18. Completely fill a pipet bulb with water and place it over the oxygen gas generator to collect oxygen

19. When the bulb is 1/6 full of gas, quickly remove it from the oxygen tube and place it over the hydrogen gas generator.

20. Continue collecting hydrogen until the bulb is filled with gas. The bulb should contain a 1:5 ratio of oxygen and hydrogen.

21. Remove the bulb, cap it with a finger, and use a match to determine its loudness (do the "pop test"). Record the results in the data table.

22. Repeat steps 18-21 to collect and test other volume ratios (2:4, 3:3, 4:2,5:1) of oxygen and hydrogen. Always collect the oxygen first, followed by hydrogen. Record all results.

23. Rank the gas mixtures on a scale from 0 to 10 to describe their relative loudness in the "pop test." Let the most explosive mixture be a 10 and the least reactive be a 0.

24. Find the optimum ratio of oxygen and hydrogen for combustion by determining which is the most explosive ratio.
ROCKET LAUNCHES!
Mole Ratio
Combustion
Stoichiometry
Limiting Reactants
2
2
HCl
5g mossy Zn
2
2
H O
2
2
2 mL yeast suspension
HCl
H O
2
2
3M HCl
full of water
3% yeast suspension
full of water
calibrated
full of water
contains hydrogen
contains oxygen
HCl
H O
2
2
full of water
1/6 oxygen gas
1/6 oxygen gas
5/6 hydrogen gas
(1:5 ratio)
ratio of hydrogen and oxygen
THANKS FOR WATCHING!
Full transcript