DID YOU KNOW?
Control Groups are a vital part of the
Scientific Method, and are used in almost
all experiments!
CONTROL GROUPS
SCIENCE
FACT PAG E
11
In this experiment, you will adjust the ratios of Vinegar (Acid)
and Baking Soda (Base). Use your distance result from your
first trial as your experiment’s
CONTROL GROUP
.
Adjust the levels of Acid and Base in small increments and
notice how your distance changes with each modification
Did your distance improve or decrease with more Acid?
Did your distance improve or decrease with more Base?
The speed and distance your Rocket Car travels is a direct
result of the power of the reaction between your Acid and Base
fuel mixtures, which is a measurement of the strength of the
Acids and Bases you
experiment with! The
stronger the Acids and
Bases, the faster and
farther your Rocket Car
will go!
EXPERIMENTING WITH FUEL RATIOS
Acids and Bases are measured by their “pH” level. The pH value
indicates the strength of the Acid or Base on a scale of 0.0 - 14.0.
Acids range from 0.0 - 6.9 and Bases range from 7.1 - 14.0.
A liquid with a pH of 7.0 is neutral, like water, and is neither
an Acid nor a Base. When Acids and Bases mix together, they
react and move towards the neutral 7.0 pH number. If the ratio of
Acid-to-Base is exactly right, they will completely neutralize each
other and the resulting mix will be a 7.0 on the pH scale.
The farther apart the pH level of the Acid and the Base, the more
vigorous the reaction and more gas is generated in the Rocket
Car fuel tank. This in turn creates more pressure in the closed
system, which then propels the Rocket Car farther and faster
when the gas is released through the nozzle! *
Use this booklet and test results to answer the following
questions:
1. Which combination of Acid and Base caused the Rocket Car
to travel the greatest distance?
2. How many feet did your Rocket Car travel?
3. What is the chemical reaction that takes place?
TRACK THE DISTANCE YOUR ROCKET CAR TRAVELS
* A relief valve is installed which will limit the pressure allowed to
build based on pre-determined safety limits.
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