Mr. Bouyer
Day 1 | Day 2 | Day 3 | Lab | Skills Test

  • Understand the concept of the mole and Avogadro's number.
  • Use factor-label to convert between moles, grams, and number of molecules.

The Mole Concept:
       This is a biology mole, NOT a chemistry mole.
There will be a formal test before Lab Day. You will demonstrate on this test that you can convert grams to moles, moles to molecules, and molecules to grams. Your paper periodic table and a "hand-held" calculator may be used during the test, but nothing else.

Read the essay by Amedeo Avogadro (1811) link to an Internet Websiteon a manner of determining the relative masses of the elementary molecules.

A Mole Is:
  • 6.02 x 1023 of anything.
  • The formula mass in grams of a substance contains one mole of particles.
  • Na = Avogadro‘s Number = 6.02 x 1023

The mole is important because:
  • It allows us to weigh atoms in the lab.
  • It allows us to compare amounts of atoms in chemical reactions.
Explore this Internet Website about Chemistry

Basic mole calculations: convert mass to moles, and moles to molecules or atoms.

These equalities are used in mole calculations:

1 mole = 6.02 x 1023atoms or molecules = formula mass in grams

Examples of Mole Conversion Problems:

These problems are set up correctly using Factor Label. Use a calculator to find each answer with the proper number of significant digits.

  1. Given 12.011 grams of carbon, how many atoms do you have?

    answer = 6.02 23 atoms

  2. Given 18 grams of water, how many molecules do you have?

    answer = 6.0 23 molecules

  3. Given 3.5 moles of sodium chloride, how many grams do you have?

    answer = 200g NaCl

  4. What is the mass of 6.02 x 1023 molecules of silver nitrate?

answer = 170g silver nitrate

 

Factor-label tips:

Setting up the factor-label problem is just as important as the answer
Form the habit of working neatly, canceling units, and circling the answer
Remember, units are just as important as numbers in the answer

Mole Calculation Practice Problems.
Show the factor-label calculation used to work each problem.

  1. What is the mass in grams of 0.452 mole of C6H12O6?
  2. Calculate the mass in kilograms of 0.681 mole of ammonia gas, NH3.
  3. Determine the number of potassium ions in 3.05 mole of K+.
  4. How many molecules are in 39.0 grams of Fe2S3?
  5. Calculate the mass in grams of 2.23 moles of nitrogen molecules.
  6. How many atoms are in 6.4 grams of copper?
  7. A raindrop contains about 0.05 grams of water.
    1. How many molecules of water are in a raindrop?
    2. How many atoms of hydrogen are in a raindrop?
    3. How many atoms of oxygen are in a raindrop?

Use this webtest link to an Internet Websiteto practice mass, mole, and formula mass (GFW).

link to a local webpage with useful information


Research Links:

Chemistry Class

 

 

 

 

 

 

 

 

Practice problem answers: