Conservation of Mass Activity Worksheet Instructions: Observe and analyze the interactions between the substances pictured in the slide show. Compare the properties of the substances before and after each interaction. You will submit your completed worksheet for grading.

Data Table

On the table below, record your observations before and after the interactions and explain how mass was conserved. Describe the changes in properties that prove a chemical reaction occurred. The first row is an example.

Observations Before Interaction

Observations After Interaction

How was mass conserved?

Proof of a Chemical Reaction

Example: Sugar + Heat:

Observations Before Interaction

The sugar is in tiny white particles in a pile. Heat is not seen but is implied by the heat source. The pile of sugar in the pot has a mass of 100 grams.

Observations After Interaction

There is a solid, light brown mass at the bottom of the pot. It has a mass of 100 grams.

How was mass conserved?

The mass of the sugar is the same in melted form as it is in solid crystal form.

Proof of a Chemical Reaction

There was not a chemical reaction. Sugar did not change the composition. It only melted. Melting point is a physical property, and this is a physical change.

Do This For

Steel Wool + Oxygen (Fire)

Egg + Heat

Water + Heat

Zinc + Hydrogen Chloride

Sodium Hydroxide + Copper Sulfate