Physics
Lab 2.1 Hydrogen
Overview
The purpose of this laboratory class is to use chemical
reactions to produce hydrogen gas and to demonstrate some
of the properties of hydrogen. The small size of hydrogen
molecules can be illustrated by comparing the ability of
a balloon to contain hydrogen compared with air.
Experiments
1. Use a small piece of
aluminum and 10% HCl to make hydrogen gas in a small
glass beaker
2. Use hydrochloric acid
and granulated zinc in a polyester soda bottle to make
hydrogen gas
3. Fill two balloons
– one with hydrogen and the other with air. Allow to
stand for 2 or 3 hours and compare the differences in
size.
Equipment
Glass beaker
Polyester soda bottle
Granulated zinc
Hydrochloric acid (Muratic acid)
Balloons
PVC gloves
IMPORTANT
SAFETY INSTRUCTIONS
- Heat is generated
during many chemical reactions. The reaction
between acid and aluminum starts slowly but
speeds up considerably once the protective layer
of oxide on the surface of the aluminum is
removed. The reaction generates much more energy
than the reaction between acid and zinc. A heat
resistant glass container must be used for the
reaction between aluminum and acid.
- Concentrated
hydrochloric acid is extremely corrosive.
- Wear eye protection
at all time while working with acids and
corrosive chemicals.
- Wear vinyl gloves
while working with acids.
- Hydrogen gas is
highly flammable and can be explosive. Work in a
well-ventilated area and do not attempt to ignite
more than 50 cm3 of hydrogen at any
time.
- Do not eat while
working with chemicals.
- Rinse thoroughly with
water if acid comes into contact with skin or
clothing.
Procedure
- Dilute the acid to
between 10% and 15%
- Place granulate zinc
in the soda bottle and cover with diluted acid.
- Collect hydrogen in a
balloon as illustrated in the video lesson.
- Use some small pieces
of aluminum foil in stead of zinc and compare the
rates of hydrogen production.
Questions
- Is hydrogen lighter
than air? How can we illustrate this?
- Why are foil-lined
balloons more suitable than conventional balloons
for containing light gases like helium and
hydrogen?
- Is hydrogen gas
flammable or explosive?
Answers
|
