03- The Mole & Avogadro's Constant.notebook

Amedeo Avagadro

Read section 5.1

*p. 224 - 232

In 1811, Amedeo Avagadro determined that any

Using carbon-12 as an example, he showed that 6.02 x 10atoms of carbon-12 had a mass of 12.01 g. This value of 12.01 i

This remains true for any element or molecule you choose. NaCl has an

6.02 x 10 molecules of NaCl, you find that it has a mass of 58.44 g.

03- The Mole & Avogadro's Constant.notebook

. If we look at a

Similarly:

http://ed.ted.com/lessons/daniel-dulek-how-big-is-a-mole-not-the-animal-the-other-onehttp://www.slideshare.net/pakliam/green-pea-analogy

A mole is just quick way of summarizing large quantities of particles (Ex. atoms, molecules, ions, formula units).

Earth has an equatorial circumference of 40 076 km. If you lined up 22 grains of sand, end to end, the line would be 1.0 cm. If you could line up one mole of grains of sand, end to end around Earth, how many times would the line encircle the planet?

Just how big is 6.02 x 1023 anyway?

*More practice: p. 228 #5

6.02 x 1023 grains of sand x 1.0 cm x 1 m x 1 km x 1 time around100 cm 1000 m 40 076 km22 grains of sand

= 6.8 x 1012 times around!

03- The Mole & Avogadro's Constant.notebook

Mole Day: 6:02 am - 6:02 pm; Oct. 23rd

6.02 x 1023

...now you know!

Converting moles to # of particlesExample 1:

How many atoms of each element are in 1 mol of H2O? How many atoms in total?

1 mol H2O = 6.02 x 1023 molecules of H2O.

03- The Mole & Avogadro's Constant.notebook

Converting moles to # of particles (cont'd)Example 2: 1 mol CaCO3 = 6.02 x 1023 formula units of CaCO3.

How many atoms of each element are in 1 mol of CaCO3? How many atoms in total?

A# particles (atoms, molecules, ions)

# moles (mol)

Avogadro's #: 6.02 x 1023 particles/moln NA

N

03- The Mole & Avogadro's Constant.notebook

How many molecules of CO

GIVEN: n = 1.65 molNA = 6.02 x 1023 molecules/mol

N = n x NA

Example 3:

ANSWER: There are 9.93 x 1023 molecules of CO2, 9.93 x 1023 atoms of C and 1.99 x 1024 atoms of O.

Converting moles to # of particles (cont'd)

Example 4:

Pentane, C5H12, is used in the production of styrofoam. How many molecules are in a 3.37 mol sample? How many carbon atoms? Oxygen atoms?

Converting moles to # of particles (cont'd)

03- The Mole & Avogadro's Constant.notebook

Converting # of particles to molesExample #1:Car batteries are made with a combination of lead plates, lead (IV) oxide plates, and sulfuric acid. One lead plate in a battery contains 2.91 x 1024 atoms of lead. What amount (in moles) of lead is in one lead plate?

Converting # of particles to moles (cont'd)Example #2: A sample of sodium bisulfite, NaHSO3, contains 2.31 x 1025 atomsof oxygen. What amount (in moles) is the sample?

03- The Mole & Avogadro's Constant.notebook

Homework: Read section 5.1 (p. 224 - 232)Answer questions- p. 230 # 11 - 19 (odd), 20; p. 231 #21, 23, 26