Kitchen Chemistry Experiment 12
Micro-Reaction Lab:
Gas Producing Reactions
Procedure
- Use one
piece of each solid (Cu (s) and Mg (s)) or the tip of a spatula
for granular solid (Na2CO3 (s), CaCO3 (s) and yeast).
- Use 8-10
drops of each solution required.
- Note
any bubbling or fizzing action as the production of a gas.
- Write
a balanced formula equation for the reactions that do occur.
Include physical state symbols for the reactants and products.
Use the Activity or Electromotive Series for II and III. IV and
V are special reactions with three products.
- There
should be three different gases produced in this set of micro-reactions.
What are the three gases? What tests could you perform to verify
your hypotheses?
-
Data
and Observations
I. identity
of gas produced ____________________________________
II. identity
of gas produced ____________________________________
III. identity
of gas produced ____________________________________
IV. identity
of gas produced ____________________________________
V. identity
of gas produced ____________________________________
What are
the tests that will verify the identity of these gases?
Teacher's
Notes
I. 2H2O2
(aq) --------> 2H2O (l) + O2 (g)
Yeast is a catalyst for the decomposition that produces oxygen.
II. Cu
(s) + HCl (aq) --------> No Reaction
Copper will not react with acid.
III. Mg
(s) + 2HCl (aq) ---------> MgCl2 (aq) + H2 (g)
A vigorous reaction; quickly producing hydrogen gas.
IV. Na2CO3
(s) + 2HCl (aq) --------> 2NaCl (aq) + H2O (l) + CO2 (g)
Bubbling and fizzing as carbon dioxide gas is released.
V. CaCO3
(s) + 2HCl (aq) ---------> CaCl2 (aq) + H2O (l) + CO2 (g)
Lots of bubbling as carbon dioxide is released.
Test
for:
O2 (g)
: "glowing" splint will reignite in the presence of
oxygen.
H2 (g)
: A burning splint will "POP" in the presence of hydrogen.
Hydrogen is explosive. Remember the Hindenberg?
CO2 (g)
: A burning splint will be extinguished in the presence of carbon
dioxide. It is the stuff in fire extinguishers!
