# the-mole

Document Sample

```					          The amount of a substance
that contains
6.02 x 1023 particles.

602,000,000,000,000,000,000,000
The abbreviation for mole is:

mol
   Molar mass of an element = mass in grams (g) of
a mole of atoms of that element.

Ex. C = 12.0 g, H = 1.0 g, O = 16.0 g

represents the average atomic mass (in grams)
of a mole of atoms of the element.
Simply requires basic multiplication and addition.

   Ex. What is the molar mass of water, H2O?

1 mole of water has 2 moles of hydrogen and 1
mole of oxygen.

2 mole  H at 1.0 g/mol = 2.0 g H

1 mole  O at 16.0 g/mol = 16.0 g O

= 2.0 g + 16.0 g = 18.0 g/mol
   1 mole of Al2(SO4)3 has 2 moles of aluminum, 3
moles of sulfur, and 12 moles of oxygen.

Molar mass of Al = 27.0 g/mol
Molar mass of S = 32.1 g/mol
Molar mass of O = 16.0 g/mol

2 x (27.0 g/mol) + 3 x (32.1 g/mol) + 12 x (16.0
g/mol) =
342.3 g/mol
The molar mass of H2O = 18.0 g/mol
This means 1 mole H2O = 18.0 g H2O

Therefore, we can turn this into two conversion
factors.

18.0 g    =     1 mole
1 mole          18.0 g
moles  grams     Use Molar Mass
grams  moles

Moles  grams
Ex. What is the mass of 3.0 moles Carbon?
Ex. What is the mass of 3.0 moles Carbon?

One mole of carbon weighs 12.0 g

Three moles of carbon weighs 3 x 12.0 g =

36.0 g
Mole Conversions (moles  grams)

What is the mass of 4.5 moles of H2O?

One mole of H2O =
1.0g (H) + 1.0g (H) + 16.0g (O) = 18.0g

4.5 moles of H2O = 4.5 x 18.0g = 81.0g
Mole Conversions (grams  moles)
How many moles is 44.5 g H2O?
One mole of H2O =
1.0g (H) + 1.0g (H) + 16.0g (O) = 18.0g/mol

44.5g     = 2.47 mol H2O
18.0g/mol
Mole Conversions (grams  moles)
How many moles is 2.5 g NaCl?

One mole of NaCl =
22.99g (Na) + 35.45g (Cl) = 58.44g/mol
2 sig. digs.

2.5g
58.44g/mol        = .04 mol NaCl

6.02 x 1023 moles/atoms
mole

Ex. Molecules  moles
How many moles is 9.00 x 1023 molecules of CO2?
How many moles is 9.00 x 1023 molecules of CO2?

9.00 x 1023 molecules   =   1.50 mole of CO2
6.02 x 1023 molecules
Moles  molecules/atoms
How many molecules is 1.75 moles H2O?

1.75mole x 6.02 x 1023 atoms x 1 molecule H2O
mole             3 atoms

= 3.51 x 1023 molecules H2O
How many molecules is 50.0 g H2O?

What is the mass of 9.0 x 1023 molecules
of CO2?

```
DOCUMENT INFO
Shared By:
Categories:
Tags:
Stats:
 views: 5 posted: 8/16/2012 language: pages: 16