Do Now 11/3/14  Dimensional analysis is a problem solving method we used in Unit 1! We will be revisiting it today. 1.Using dimensional analysis, solve the following problem: How many seconds are in 34.2 minutes? 2.Round your answer above to the correct number of sig figs!!  3. What numbers do you think the following words represent?  a. Paird. Gross  b. Dozen e. Gig  c. Score  Dimensional analysis is a problem solving method we used in Unit 1! We will be revisiting it today. 1.Using dimensional analysis, solve the following problem: How many seconds are in 34.2 minutes? 2.Round your answer above to the correct number of sig figs!!  3. What numbers do you think the following words represent?  a. Paird. Gross  b. Dozen e. Gig  c. Score

By the end of the class period I will be able to…  Define the term “mole”  Use the concept of mole to convert between grams and moles of an element.  Define the term “mole”  Use the concept of mole to convert between grams and moles of an element.

Topic #1 Words that stand for numbers

Pair = ? Dozen = ? Score = ? Gross = ? Gig = ?

Pair = 2 Dozen = ? Score = ? Gross = ? Gig = ?

Pair = 2 Dozen = 12 Score = ? Gross = ? Gig = ?

Pair = 2 Dozen = 12 Score = 20 Gross = ? Gig = ?

Pair = 2 Dozen = 12 Score = 20 Gross = 144 Gig = ?

Pair = 2 Dozen = 12 Score = 20 Gross = 144 Gig = 1,000,000,000

Pair = 2 Dozen = 12 Score = 20 Gross = 144 Gig = 1,000,000,000 Mole = ????

What is mole??  Mole: a unit of measurement used in chemistry to express amounts of a chemical substance  ‘Mole’ means 6.022x10 23  Mole: a unit of measurement used in chemistry to express amounts of a chemical substance  ‘Mole’ means 6.022x10 23

Avogadro’s Number The mole is a HUGE number: 602,200,000,000,000,000,000, x is also called “Avogadro’s Number”

A mole of sand grains: Would cover all of the land in the continental United States to a depth of 3 inches! Would cover all of the land in the continental United States to a depth of 3 inches!

A mole of marshmallows: Would cover all of the land in the continental United States to a depth of 600 miles! Would cover all of the land in the continental United States to a depth of 600 miles!

A mole of baseballs If you wanted to make a bag to keep these baseballs in… The bag would need to be the size of our earth. If you wanted to make a bag to keep these baseballs in… The bag would need to be the size of our earth.

If a mole of pennies: Was divided amongst every person on earth Each person would receive 1.5 x pennies Was divided amongst every person on earth Each person would receive 1.5 x pennies

That Means: Each person could spend: One million dollars a day for the next four thousand years! Each person could spend: One million dollars a day for the next four thousand years!

Conclusion: A MOLE is a really really really really really really really really really large amount.

Stop and Jot  How would you explain the definition of ‘mole’ to a 5th grader?

Representative Particle  A representative particle is the simplest unit of any substance. There are x representative particles in a mole of any substance.

Representative Particles For an element… For an ionic compound… For a covalent compound… An atom Example: Au or O 2 A formula unit Example: NaCl A molecule Example: H 2 O

So, what’s the representative particle in… A glass of water?

So, what’s the representative particle in… A roll of quarters?

Comparing Moles of Quarters and Dimes  Compare a mole of dimes to a mole of quarters.  What things would be the same? What would be different?  Done early? Try to calculate how much money each would be!  Compare a mole of dimes to a mole of quarters.  What things would be the same? What would be different?  Done early? Try to calculate how much money each would be!

Dimensional Analysis a problem solving method that allows for conversion of one unit to another

Conversion Factor: ratios used to convert a measured quantity to a different unit of measurement

The MOLE 6.022x10 23 atoms = an element’s mass # in grams 1 mole = Equivalence Statement

The MOLE 6.022x10 23 atoms = an element’s mass # in grams 1 mole = Equivalence Statement What does equivalence statement mean?

Complete the following equivalence statement: 1 Dozen = 12 items

Steps to convert : 1. Write what you are given (including units). 2. Write the unknown (what you are trying to calculate). 3. Create a conversion factor that has the given units on the denominator and the unknown units on the numerator. 1. Write what you are given (including units). 2. Write the unknown (what you are trying to calculate). 3. Create a conversion factor that has the given units on the denominator and the unknown units on the numerator.

Moles to Atoms Atoms to Moles

How many atoms are in a sample of 8.31 moles of calcium? 1 mole of atoms = 6.022x10 23 atoms = an element’s mass # in grams

How many moles are in a sample of 2.25 x atoms of neon? 1 mole of atoms = 6.022x10 23 atoms = an element’s mass # in grams

How many atoms are in a sample of 3.15 moles of phosphorus? 1 mole of atoms = 6.022x10 23 atoms = an element’s mass # in grams

How many moles are in a sample of 4.10 x atoms of potassium? 1 mole of atoms = 6.022x10 23 atoms = an element’s mass # in grams

Moles to Grams Grams to Moles

How many moles are in a sample of 4.55 grams of carbon? 1 mole of atoms = 6.022x10 23 atoms = an element’s mass # in grams

How many grams of carbon are in a mole sample of carbon? 6.022x10 23 atoms = an element’s mass # in grams 1 mole =

How many grams of magnesium are in 5.34 moles of magnesium? 6.022x10 23 atoms = an element’s mass # in grams 1 mole =

How many moles of nitrogen are in grams of nitrogen? 6.022x10 23 atoms = an element’s mass # in grams 1 mole =

Atoms to Grams Grams to Atoms

What is the mass of 1.47 x atoms of lead? 1 mole of atoms = 6.022x10 23 atoms = an element’s mass # in grams

How many atoms of nickel are in grams of nickel? 6.022x10 23 atoms = an element’s mass # in grams 1 mole =

How many grams of bromine are in 8.02 x ions of bromine? 6.022x10 23 atoms = an element’s mass # in grams 1 mole =

How many atoms would you have if you measured out 36.8 g of sodium? 1 mole of atoms = 6.022x10 23 atoms = an element’s mass # in grams

Assignment… Molympics Prep Worksheet 1 mole of atoms = 6.022x10 23 atoms = an element’s mass # in grams

1. What does “mole” mean in chemistry? 2. What is Avogadro’s number? 3. What is the mass in grams of moles of iron? 1 mole of atoms = 6.022x10 23 atoms = an element’s mass # in grams