Lab 4B – Putting Bubbles to the Test
Answers
1.
Tube #
Material &
Amount
1
3 ml of
ammonia
solution
2 ml of lead
nitrate solution
1 small piece of
chalk
1 pinch of
baking soda
1 small piece of
zinc
2
3
4
5
Appearance
Before Adding
HCl
Clear colorless
liquid
Observable
Changes
Clear colorless
liquid
Yellow
cylindrical solid
White powder
Cloudy white
Gray solid,
rough surface,
irregular shape
Slow bubbling
Got warmer
Tiny bubbles
Rapid bubbling
2. Chalk, baking soda and zinc (all bubbled) produced a gas when HCl was
added.
3. Ammonia solution nor lead nitrate solution behaved the same way when
HCl was added to them.
4. Chalk, baking soda and zinc all had a gas bubble from them when HCl
was added to them.
Operationally defined, you know a gas is carbon dioxide if turns limewater
cloudy, phenol red to yellow, and quickly puts out a burning match.
Chalk + HCl → Carbon dioxide and Soda + HCl → Carbon dioxide