Barking Dog Lab
use your knowledge of writing and balancing equations to predict the products
of two reactions.
Ringstand†††††††† ††††††††††† ††††††††††† Pneumatic
Trough†††††††† ††††††††††† Rubber Stopper
Erlenmeyer Flask††† ††††††††††† Test Tubes†††††††††††††† ††††††††††† Glass
Aluminum Foil† ††††††††††† Matches†††††††††††††††††††††† ††††††††††† 6.0
an Erlenmeyer flask attached to a ring stand with a stopper and tube
attachment.† Also obtain a small
piece of Aluminum Foil.
your SAFETY GOGGLES ON!† DO NOT TAKE THEM OFF DURING THE ENTIRE LAB! OTHER GROUPS
WILL STILL BE WORKING!
out 20.0 mL of
6.0 M HCl and pour it into the flask.†
BE VERY CAREFUL AS ACID WILL BURN SKIN.† IF YOU GET ANY ACID ON YOU, BE SURE TO RINSE IMEDIATELY WITH
WATER AND PUT BAKING SODA ON THE AFFECTED AREA.
your test tubes HALF-WAY with water
and set them up in the Pneumatic Trough so that they are upside down.
you are ready, crumple the Al foil into a light ball and put it in the
Erlenmeyer flask.† PUT THE STOPPER ON FIRMLY!† The pressure inside the flask will
build and you donít want the stopper to pop off!† (If it does pop off, donít panic!† Just be sure to rinse off any acid that might get on you and
call me over immediately!† If the
rubber stopper pops off, it rarely splashes acid, but please be careful
and be prepared.)
a few seconds, the reaction will take place.† It happens RAPIDLY so work quickly.† Put the hose UNDER THE WATER when you
put the stopper in place. When the reaction begins, collect the
bubbles under the test tubes.† When
the bubbles are all collected, lift the test tubes (one at a time) out of
the Pneumatic Trough and light a match underneath the mouth of the test
tube.† Donít turn the test tubes
over (so their mouths are pointing up) or else youíll lose all the Hydrogen
and have nothing to light. DONíT LIGHT THE HOSE COMING FROM THE ERLENMEYER!
your matches in the pneumatic trough BEFORE putting them in the trash
can.† We donít want any trash can
Answer these before doing the lab.† You must write the question and then answer it.†
the Aluminum foil be crumpled up tight, loose or left as a flat sheet?
you put the stopper on firmly or lightly?
many mL of acid are you going to add to the Erlenmeyer flask?
much water should you put in the test tube?
should you put the hose from the Erlenmeyer immediately after you put the
stopper in place?
should you hold the test tubes so that you can light them?
should you do if the stopper pops off and/or you are splashed with acid.
youíre done with your matches, where should you put them BEFORE they go in
the trash can?
type of reaction is occurring in the Erlenmeyer Flask? (Synthesis, Decomposition, Single Displacement, Double
Displacement or Combustion).
out a BALANCED equation for the reaction in the Erlenmeyer flask.† (Youíll need to determine the oxidation
number of Aluminum.† Also, remember
that Hydrogen, when it is by itself, is diatomic.)
are the reactants in this equation?
are the products in this equation?
at your balanced equation (from Question #2).† If you had 4 moles of Aluminum for this reaction, how many
moles of Hydrogen would you produce? (Realize that equations are balanced
in moles, so an equation simply tells you the ratio of moles of reactant
to moles of product)
type of reaction is occurring in the test tube?† (Synthesis, Decomposition, Single
Displacement, Double Displacement or Combustion).
out a BALANCED equation for the reaction in the test tube.
are the reactants in this equation?
are the products in the equation?
- †Look at the balanced equation (from
Question #7).† If you had 2 moles
of oxygen, how many moles of water would be produced?
- Why do
you think I asked you to fill the test tube half-way with water. †Why not all the way full?
What is due for this lab?
Turn in the pre-lab questions and the questions only.†
Be sure you copy the questions before you
answer them.† You can always print them
out and answer them that way.
†† NEATNESS† COUNTS