The purpose of this experiment is to examine different properties of gases in order to be able to identify them in a laboratory setting. I will be using Hydrochloric acid, mossy zinc, Bromothymol blue, limewater, Manganese, and Alka Seltzer, to test different properties of gases formed by chemical reactions. In order to extract the gas I will use several household products such as vinegar, baking soda, water, and hydrogen peroxide in order to create the gases to be tested.
1 Toothpicks (or wooden splints)
1 Pie tin or similar
1 Marker pen
1 Household white vinegar
1 3% Hydrogen peroxide (H2O2)
1 Measuring spoons
1 Drinking straw
1 Tissue paper
1 Baking soda (sodium bicarbonate)
From LabPaq 1 Goggles-Safety
1 Test Tube (5), 13 x 100 mm in Bubble Bag
1 Gas Assembly; copper/plastic tubing in #00
1 Pipet, Empty Short Stem
1 Rubber stopper, #00, 1 hole, Pipet tip w/plastic
Gas delivery tube
Experiment Bag Properties of
Gases 2 Alka Seltzer® (1/4 tablet) in Bag 2″ x 3″
1 Bromothymol Blue, 0.04% – 4 mL in Pipet
1 Hydrochloric Acid, 2 M – 20 mL in Dropper
1 Limewater (Calcium Hydroxide, Saturated) – 6
mL in Pipet
1 Manganese Metal Pieces – 4-6 Pieces in Bag 2″
3 Pipet Bulbs, Wide-Neck with 1/4″ Stem
1 Zinc, Mossy – 4-6 Pieces in Bag 2″ x 3″
a) I placed a small amount of ZN( mossy zinc) in the test tube containing HCL b) I then capped the test tube with the small cap that allowed gas release from the top and placed it in one of the 24 well plates. I wedged the test tune in with a bit of toilet paper. c) I then filled the large stem pipet with water and placed it atop the rubber stopper. d) I placed the well plate in a pie tin to prevent the overflow from getting everywhere. e) After the water was replaced entirely with hydrogen I removed the wide mouthed pipet and placed my finger over the opening to prevent any gas from escaping. f) I lit a match and while holding the pipet about 1cm away from the flame blew the gas onto the flame, and recorded my observations in the table. g) With a marker I marked the wide-neck pipet on the outside into three parts h) I filled the bulb with water and set it on the test tube as before. i) Once the bulb was 2/3 full of gas I removed it and placed it aside, still inverted, for later use j) I then disassembled and rinsed the tools and threw away the ZN.
A) I placed a few pieces of Mn (Manganese) into the second test tube. B) I filled the test tube to within 1cm of the top with hydrogen peroxide. Afterwards I placed the rubber stopper on the test tube and the test tube in the well plate. . C) I then filled another wide-neck pipet completely with water and placed it on the top of the stopper in the test tube. D) After the water was displaced I removed the pipet and placed my finger over the opening to prevent any gas from leaking. E) I lit a match and extinguished it. While the match was still glowing I placed it inside the pipet and recorded the reaction.
3) Hydrogen and Oxygen Mixture
A) I took the pipet from part 1 that is partially filled with hydrogen and placed it on the generation test tube from part 2. B) I let the bulb fill until the water was completely displaced. The mixture was about 2/3 hydrogen and 1/3 oxygen C) I removed the bulb and placed my finger over the open end to prevent any gas from escaping D) I lit a match, held the pipet horizontally about 1cm away from the flame and squeezed the gas onto the flame. E) I recorded my observations in the table.
F) I disassembled the test tube washed the contents down the drain and rinsed the tools.
4) Carbon Dioxide
A) Part I
a) I placed approximately .5 ml of limewater in one well of the 24 well plate. b) I placed ½ a teaspoon of baking soda in the generation test tube. c) I filled a pipet halfway with vinegar and added it to the baking soda. Immediately after the two stopped reacting I placed the rubber stopper with the copper and plastic gas delivery tube on the top of the test tube. d) I placed the open end of the tube into the well with limewater and recorded the reaction.
B) Part II
a) I placed approximately .5ml of Bromothymol blue in one of the wells. b) I thoroughly rinsed the gas generation test tube with water and set up another test with baking soda and vinegar as in part 1. c) After putting the stopper in place I inserted the open tube into the Bromothymol blue. d) I removed the stopper from the generation tube.
e) I lit a match and inserted the flame into the upper part of the test tube.
f) I recorded my observations.
C) Part III
a) I poured the chemicals down the sink and flushed with water.
b) I put approximately .5 ml of limewater into another well.
c) I crumbled the small piece of Alka Seltzer into a test tube
d) I added one pipet full of water to the test tube and immediately inserted the stopper with the gas delivery tube.
e) I placed the open end of the tube into the limewater well.
f) I washed the test tube and well thoroughly with water.
D) Part IV
a) I put approximately .5 ml of limewater into a test tube.
b) I inserted a straw and blew for a few seconds.
c) I recorded my observations
d) I washed the tools and flushed the limewater down the sink.
Bromothymol blue reaction
Loud sound, flame went out
Light up quickly dissipated and glowed for around 10 seconds n/a
Hydrogen & oxygen
Popping sound and flame went out
Changed the color of the limewater from clear to nearly milky, bubbled rapidly. Bubbled rapidly, changed colors slightly to green
Lots of pressure in the test tube, color change in limewater from clear to nearly milky, rapid small bubbles
Very large bubbles, color change from clear to nearly milky. n/a
A) Give two reasons why we fill gas generator test tubes almost to the top with chemicals. First we do this because maximizing the pressure in the tube will maximize gasses. Secondly because this causes there to be a shorter distance for the gases to traveled
B) What happens to the zinc in the hydrogen generation experiment? The mossy zinc causes a reaction with the HCL to form hydrogen gas.
C) What happens in the oxygen generation experiment?
The manganese reacts with the hydrogen peroxide to form oxygen.
D) Write a balanced equation for the reaction between O2 and H2. 2H2 +O2—>2H2O
E) What is the function/purpose of the Bromothymol blue in the CO2 experiment? The Bromothymol blue in the CO2 experiment is used to indicate how much CO2 is in the solution. It indicates this with a color change.
F) Bromothymol blue is blue in the presence of basic solutions and yellow in the presence of acidic solutions. If your solution is a murky green, what might you assume about the solution I would assume the solution was neutral.
In conclusion, I learned that properties of gases vary vastly in their reactions with flame, and other substances. I also learned how to create such gases in a controlled environment for future experimentation. The effect of these reactions put into perspective how dangerous gases can be and how their proper storage and transportation is a vital essential in our daily lives. Seeing the different reactions will make me more cautious of the way I materials.