SNC 1D1-Lab
What is this gas?
Name: ________________
Background: Imagine you are a technician in a chemical lab. While
cleaning up after a flood in the laboratory, you discover that the
labels on three cylinders of gas have been damaged, you suspect
that the cylinders contain carbon dioxide, hydrogen, and oxygen, but
you don’t know which cylinder contains which gas.
The fire triangle:



Oxygen is essential for burning. Things burn more vigorously when they are in pure
oxygen than when they are in air, which contains only about 20% oxygen.
When Hydrogen is ignited in air, the hydrogen atoms combine with the oxygen atoms to
form molecules of H20 (water vapour). This rapid reaction is accompanied by a
characteristic explosive “pop” sound.
Carbon dioxide does not burn and does not support combustion. Carbon dioxide will
extinguish a flame, making it useful as a fire extinguisher.
Demo Experiment:
1) What are the reactants? ________________ and _____________________
2) Draw a diagram of the experiment set-up (3 marks)
3) What happened? ____________________________________________
4) Based on the result, what was the gas produced? ___________________
Lab Instructions:
1) Put on eye protection
2) For experiment#1: a) Fill a test tube until it is overflowing with water.
b) Fill a beaker ½ full of water.
c) Place a bit of paper towel over the top of the test tube.
d) Invert the test tube in the beaker
e) Your teacher will put a piece of calcium into the beaker
f) Place the inverted test tube over the calcium and collect the gas for 1-2 minutes
g) Lift the test tube out of the beaker but do not turn it right side up
h) Introduce first a glowing splint, and then a flaming splint
i) record your observations
j) rinse out your materials and return the station to its original state
3) For experiment#2: a) Put a heaping scoopula of manganese dioxide into a test tube
b) Add hydrogen peroxide to the same test tube until it is about 1/3 full.
c) Place the stopper on the test tube and while holding the stopper down with your
thumb, gently agitate for approx. 2 minutes.
d) When there is some pressure on the stopper, remove it and introduce first a glowing
splint, and then a flaming splint.
e) Record your observations.
f) Rinse out your materials and return the station to its original state.
4) For experiment#3: a)Put a heaping scoopula of sodium bicarbonate into the little
graduated cylinder.
b) Add 1/3 of a graduated cylinder of acetic acid.
c) Quickly place the larger beaker over the graduated cylinder
d) Let the reaction proceed for approx. 2 minutes
e) Introduce first a glowing splint, and then a flaming splint
f) Record your observations
g) Rinse out your materials and return the station to its original state
SNC 1D1
Experiment
Identifying Mystery Gases Lab
Reactants
1
List 2 physical properties of
each reactant
-
Name: _____________________
Observations of mixture
Results of Splint Tests
Burning splint-
Calcium
Dihydrogen
Monoxide
2
-
Hydrogen
3eroxide
Glowing splint-
Burning splint-
Glowing splint-
Manganese
dioxide
3
-
Acetic
acid
Burning splint-
Glowing splint-
Sodium
bicarbonate
-
Identity of Gas
Discussion questions:
1.
What is the difference between a burning splint and a glowing splint?
2.
What gas were you testing for with the:
a) Burning splint?
b) Glowing splint?
3.
Which gas seemed the most hazardous in this activity? Why?
4. In each experiment, were the changes physical or chemical? Justify your answer. (6 marks)
5. What problems, if any, did you encounter with any of these experiments?
6. From your observations in this activity suggest reasons why…
a) birthday balloons are filled with helium, not hydrogen
b) during surgery using oxygen cylinders, medical staff wear coverings over their shoes to eliminate sparks
produced by static electricity
/40 marks