Moles

The Mole

• This is a unit of measurement.

Moles

• 1 mole = 6.02x 1023 particles

Substances Element Ionic Compound

Molecular Compound

Representative particle

Atom Formula Units

Molecules

Example Sodium Sodium

Chloride

Water

Mass Use: Atomic mass

Use:

Formula Unit

Use:

Molecular mass

Find amount of particles and weight

1 mole of copper atoms=

1 mole of NaCl Formula units=

1 mole of water molecular units=

1 mole of copper atoms= 6.02x1023 atoms= 63.5g

1 mole of NaCl Formula units= 6.02x1023 fu 58.5g

1 mole of water molecular units= 6.02x1023 mc= 18g

Avagadro’s number

= 6.02x1023 particles

In a lab 0.36mol Al are needed. How many particles is that? What type of particle is this?

In a lab 0.36mol Al are needed. How many particles is that? What type of particle is this?

0.36mol X 6.02x1023 particles = 2.1672 x1023

1 mol Al

2.2 x1023 atoms

How many moles of Na2CO3 contain 7.9x1024 f. units?

How many moles of Na2CO3 contain 7.9x1024 f. units?

7.9x1024 f.units x 1 mole

6.02x1023 f.units

13.1229 13 moles

Mole to mass problems

• What is the molar mass of these substances?

PbH2O Cu Al NaCl

If you had 3.5 moles of Pb what is the mass

If you had 3.5 moles of Pb what is the mass

3.5 mol Pb x 207.2g Pb 725.2g

1 mol Pb

730g

If I had 125.1 g H2O how many moles is that?

If I had 125.1 g H2O how many moles is that?

125.1g H2O x 1mol H2O 6.950mol

18.0g H2O

6.950mol

In groups

You have 6.0 moles of oxygen gas, what is the mass?

You have 6.0 moles of Oxygen gas, what is the mass?

6.0moles O x 32.0g O 192 grams

1mol O

=200g

In groups

The mass of a sample of ammonia is 232grams. How many moles are in the sample?

The mass of a sample of ammonia is 232grams. How many moles are in the sample?

232g NH3 x 1 mol 13.647mol

17.0 g

13.6 mol

Volume

1 mole of any gas at STP has a volume of 22.4L

STP=Standard Temperature and Pressure

0o C and 1 atm

1 mol gas = 22.4L

If you have 3.5 mol of O2 gas what is the volume?

If you have 3.5 mol of O2 gas what is the volume?

3.5 mol O2 x 22.4 L O2

1 mol O2

78.4 L

78L

If a gas has a volume of 10.0L, how many moles is that?

If a gas has a volume of 10.0L, how many moles is that?

10.0 L x 1 mol

22.4 L

=0.4462 mol

0.446 mol

What is the unit/ type of particle/ amount for Representative particles for each of the following:

Matter: Element Ionic cmpd Molecular cmpd

R. Part.Type: _______ __________ ____________

Unit: _______ ______________________

AmountOf Part. _______ ______________________

What is the unit/ type of particle/ amount for Representative particles for each of the following:

Matter: Element Ionic cmpd Molecular cmpd

R. Part.

Type: atoms formula units molecules

Unit: atoms formula units molecules

Amount

Of Part. 6.02x1023 atoms 6.02x1023 formula units 6.02x1023 molecules

SOLVE

Convert 0.50 moles of ammonia vapor to liters.

How many particles are in 0.35 mol of CaCl2

(what type of particles will we have?)

Convert 0.50 moles of ammonia vapor to liters.

0.50 mol x 22.4 L

1mol =11.2L = 11L

How many particles are in 0.35 mol of CaCl2

(what type of particles will we have?)

0.35 mol x 6.02x1023 f.units

1mol

=2.107x1023 f.units

= 2.1x1023 f.units

Mole to Mole Ratio’s

Balance:

Mg + O2 MgO

N2H4 + N2O4 N2 + H2O

2 Mg + O2 2 MgO

2 N2H4 + N2O4 3 N2 + 4 H2O

Coefficients represent the number of moles for each element. This gives us a ratio in the rnx.

2 Mg + O2 2 MgO

____Mg:____MgO

____Mg:____O2

____O2: ____MgO

2 Mg + O2 2 MgO

__2__Mg:__2__MgO

___2_Mg:__1__O2

__1__O2: __2__MgO

2 Mg + O2 2 MgO

If 3.5 moles of Mg react __(#1)___moles of O2 to produce __(#2)__ mole of MgO

#1

3.5 mol Mg x 1 mol O2 =1.75 mol O2

2 mol Mg = 1.8 mol O2

#2

3.5 mol Mg x 2 mol MgO = 3.5 mol MgO

2 mol Mg

If 3.5 moles of Mg react __1.8___moles of O2 to produce _3.5___ mole of MgO

2 N2H4 + N2O4 3 N2 + 4 H2O

3.75 moles of N2O4 Find the other amount of moles needed.

If 3.75 mol N2O4 rnx with ____ mol N2H4 they will produce ___ mol N2 and ___ mol H2O.

2 N2H4 + N2O4 3 N2 + 4 H2O

3.75 mol N2O4 x 2 mol N2H4

1 mol N2O4 =7.50 mol N2H4

3.75 mol N2O4 x 3 mol N2

1 mol N2O4 =11.25 mol N2

=11.3 mol N2

3.75 mol N2O4 x 4 mol H2O

1 mol N2O4 =15.0 mol H2O