Tuesday11/7/12

Bell Ringer

1) Get out your composition notebook to finish taking MOLE notes!

*YOU WILL NEED A CALCULATOR ALSO

Schedule1. Bell Ringer—Go over

Ch. 6 Test

2. Molar Conversion notes & practice

3. Practice Problems—on agenda (Questions 1-4, 6-9 & Paired Exercises 12-28 EVENHOMEWORK: Work on

Book Problems

PAP Chemistry

Teachers open the door, but you must enter by yourself.

I CAN……solve chemistry problems by being an independent, creative thinker.

I II III IV

Ch. & 7 – The Mole

I. Molar Conversions

Why learn about the mole?

It’s not practical to do chemical reactions by counting the number of atoms or molecules out, bc you would be counting for a VERY long time.

WE use the mole like you would a dozen, a ream, a bushel, etc….

A. What is the Mole? A counting number (like a dozen)

Avogadro’s number (in honor of the dude who first

worked with it)

1 mol = 6.022 1023 anything

One mole of anything is the amount of substance that

contains the same number of items as there are atoms in

exactly 12 g of Carbon-12

602,200,000,000,000,000,000,000,000

A large amount!!!!

1 mole of hockey pucks would equal the mass of the moon!

A. What is the Mole?

1 mole of pennies would cover the Earth 1/4 mile deep!

1 mole of basketballs would fill a bag the size of the earth!

B. Molar Mass The atomic mass of an element in

grams

Mass of 1 mole of an element or

compound.

Atomic mass tells the... atomic mass units per atom (amu) grams per mole (g/mol)

Round to 2 decimal places

B. Molar Mass Examples

carbon

aluminum

zinc

B. Molar Mass Examples

water

sodium chloride

H2O

2(1.01) + 16.00 = 18.02 g/mol

NaCl 22.99 + 35.45 = 58.44 g/mol

B. Molar Mass Examples

sodium bicarbonate

sucrose

NaHCO3

22.99 + 1.01 + 12.01 + 3(16.00)

= 84.01 g/mol

C12H22O11

12(12.01) + 22(1.01) + 11(16.00)

= 342.34 g/mol

C. Molar Conversions

molar mass

(g/mol)

MASS

IN

GRAMS

MOLESNUMBER

OF

PARTICLES

6.02 1023

(particles/mol)

C. Molar Conversion Examples How many moles of carbon are

in 26 g of carbon?

26 g C 1 mol C

12.01 g C= 2.2 mol C

C. Molar Conversion Examples How many molecules are in

2.50 moles of C12H22O11?

2.50 mol6.02 1023

molecules

1 mol= 1.51 1024

molecules C12H22O11

C. Molar Conversion Examples Find the mass of 2.1 1024

molecules of NaHCO3.

2.1 1024

molecules 1 mol

6.02 1023

molecules

= 290 g NaHCO3

84.01 g

1 mol

C. Molar Conversion Examples1. How many oxygen atoms are

present in 1.00 mol of oxygen molecules?

2. How many moles of sodium hydroxide (NaOH) are there in 1.00 kg of sodium hydroxide?