Conservation of Matter Lab

The law of conservation of matter states that matter cannot be created or destroyed in an ordinary chemical reaction. Another way of stating this is that the mass of products of a chemical reaction is always equal to the mass of the reacting materials. No one has ever found an exception that does no fit this law. Your task is to devise and conduct an experiment that tests the law of conservation of matter.

You may study one of two reactions:

Burning a wax candle

The solid wax reacts with oxygen in the air, forming carbon dioxide gas and water vapor.

OR

The alka seltzer reaction

Alka seltzer tablets contain citric acid and baking soda. When added to water, the reaction produces carbon dioxide gas, water, and a soluble compound called sodium citrate.

Equipment and Materials:

Burning of Wax

Reaction of alka seltzer

Triple beam balance

Triple beam balance

4 birthday candles

1 balloon

Matches

Water

Graduated cylinder

2-liter soda bottle

Bottles with stoppers

4 alka seltzer tablets

String

Grading Scale:

Your lab report will be graded on the following criteria:

The problem is clearly defined.
An appropriate experimental design has been selected and employed.
Reasoning is logical and explained thoroughly.
Inferences and conclusions are supported by appropriate observation or data.
There are few misconceptions or serious errors.
The methods and results are communicated clearly enough that the reader could easily repeat the experiment.

You will have one class period to conduct the experiment. You will have a portion of another class period to write it up in your lab book.

Data Analysis:

You must show mathematically, using your data, that the total mass of the reactants equals the total mass of the products in a closed system. If you are investigating an open system, in which gaseous products escape, show that the initial mass is greater than the final mass of the system.