Counting by Measuring Mass Lab

Ms. Mai

Lawndale High School

You will be working in groups of 4 I only need 1 paper turned in by the end of the period

Purpose

To measure the mass of three samples of compounds (chalk, salt, and water)

Then, use the data to calculate the number of atoms in each sample

Materials

3 plastic containers Chalk Salt Water Electronic Balance

Procedures

1. Measure the mass of one teaspoon of each chemical in the plastic container

2. Record the mass in your data table

3. When you have measured the mass of your sample, pour the salt and chalk back into the appropriate containers. You can just pour the water down the sink.

Data TableH2O (l) NaCl (s) CaCO3 (s)

Mass (g)

Molar Mass (g/mol)

Moles of each Compound

Moles of each Element

Atoms of each Element