BACKGROUND INFORMATION
Most of the gases in our air are often colourless and odourless. Although they are
indistinguishable in appearance they have different chemical properties.
Oxygen is needed for burning. Things tend to burn more in the presence of oxygen.
Hydrogen burns and reacts so quickly with the oxygen atoms in the air (to make water vapour),
that the reaction has a characteristic explosive ‘pop’ sound. Carbon dioxide does not burn and
extinguishes or puts out a flame, making it useful in fire extinguishers.
Purpose:
To produce different gases and identify each gas using a chemical test.
Equipment and Materials:
- manganese dioxide
- goggles/aprons
- wooden splints
- sodium bicarbonate (baking soda)
- 3-5 test tubes
- matches
- magnesium ribbon
- test tube rack
- masking tape
- 3% hydrogen peroxide
- test tube cleaner
- acetic acid (vinegar)
- test tube holder
- 1 M hydrochloric acid
- scoopula
Safety Precautions:
Be careful with the chemicals in this lab. They are toxic and corrosive. Report any spills or
accidents to the teacher. Be careful when working with the flame. Tie back long hair and loose
clothing.
Procedure:
1. Use your scoopula to obtain a tip-full of manganese dioxide. Record its physical properties in
your observation table. Place the manganese dioxide into a test tube.
2. Put a few drops (5 mL) of 3% hydrogen peroxide (from the teacher’s lab bench) into a second
and different test tube. Record its physical properties in your observation table.
3. Add the hydrogen peroxide to the test tube with the manganese dioxide and immediately cover
the mouth of the test tube with your thumb (or a rubber stopper that fits).
4. Ignite a wooden splint so there is a flame. Gently blow out the flame and place the glowing
splint into the mouth of the test tube. Do not let go of the wooden splint. Record your
observations in your observation table. Identify the gas.
5. Clean your equipment.
6. Use your scoopula to obtain a tip-full amount of baking soda. Record its physical properties in
your observation table. Place the baking soda into a test tube.
7. Put a few drops (5 mL) of vinegar (from the teacher’s lab bench) into a second (and different)
test tube with the baking soda and immediately cover the mouth of the test tube with your
thumb (or a rubber stopper that fits).
8. Light the wooden splint so there is a flame. Place the flame into the month of the test tube.
Do not let go of the wooden splint. Record the observations in your observation table. Identify
the gas.
9. Clean your equipment.
10. Obtain a piece of magnesium ribbon. Record its physical properties in your observation table.
Place it into a test tube.
11. Obtain a dropper bottle of hydrochloric acid. Record its physical properties in your observation
table.
12. Add 5-10 drops of hydrochloric acid to the test tube with the magnesium ribbon and
immediately cover the mouth of the test tube with your thumb (or a rubber stopper that fits).
13. Ignite a wooden splint so there is a flame. Place the flame into the mouth of the test tube. Do
not let go of the wooden splint. Record your observations in your observation table. Identify
the gas.
14. Clean your equipment.
Observation Table:
Substance
Manganese
dioxide
Hydrogen
peroxide
Baking soda
Vinegar
Magnesium
Hydrochloric
acid
Physical
Properties
Observations after
mixing
Reaction with flame
Identity of gas