The mol
What is it?
a word to indicate a number (6.02 x1023)
Why is it necessary?
chemicals don’t react by mass(grams)… they react with particles
(H20 is not 2 grams of H to 1 gram of O!)
… the mol will relate to the particles in equations.
How can we convert to it?
… by using CONVERSION FACTORS.
1. mol mass practice sheets d9,d10
…. the number of g/mol
see your P.T. and add up the individual atomic masses for 1 mol
eg. water = 1 +1 + 16 = 18 g/mol ?
carbon dioxide = 12 + 16 + 16 = 44 g/mol
2A. gram à mol practice sheets d13
1. 1000 g [ 1.00 mol ] = 11.9 mol
[ 84.0 g ]
2. 1000 g [ 1.00 mol ] = 9.44 mol
[ 106.0 g ]
3. 1000 g [ 1.00 mol ] = 4.06 mol
[ 246.4 g ]
4. 1000 g [ 1.00 mol ] == 6.10 mol
[ 163.9 g ]
5. 1000 g [ 1.00 mol ] = 22.7 mol
[ 44.0 g ]
6. 1000 mL water [ 1.0 g ] [ 1.00 mol ] = 55.6 mol
[ 1.0 mL] [ 18.0 g ]
2B. molà gram d15, d17,d18
Heath p.109 Q.6-14
Example
0.21 mol (NaCl) [ 58.5 g ] = 12. g NaCl
[ 1.00 mol ]
1. 0.100 mol (KHC4H4O6) [ 188.1 g ] = 18.8 g
[ 1.00 mol ]
2. 3.9 x 102 g
3. 19 g
4. 1.00 x 103 g
5. 3.9 g
6. 68.9 g
Notice that chemicals react by mol not grams!
2 H2O à 2 H2 + 1 O2
36 g à 24 g H and 12 g O wrong!
Convert 36 g to mol x [1.00 mol] = 2.00 mol H2O
[18.0 g ]
How many mol of H2 would be made?
Look at the equation coefficients
2.00 mol of H2 are made. How many grams?
2.00 mol H2 [ (1.0 + 1.0= 2.0 g)] = 4.0 g H2
[ 1.00 mol H2 ]
How many mol of O2 should be produced?
1.0 mol according to the equation coefficients.
What is the mass of 1.0 mol of O2?
32.0 g
So 36 g of water produces 4 g H2 and 32 g O2
3A. mol à particles (atoms or molecules)
a. How many atoms of C in 2.0 mol of CO2 ?
b. How many atoms of O in 2.0 mol of CO2?
c. How many molecules of CO2 in 2.0 mol CO2?
2.0 mol CO2 [ 6.02 x 1023 molecules] =1.204 x 1024 molecules
[ 1 mol CO2 ]
1.204 molecules CO2 [ 1 atom C ]= 1.2 x 1024 atoms
[ 1 molecule CO2]
2.0 mol CO2 [ 6.02 x 1023 moleculesCO2] [ 1 atom C ] = 1.2 x 1024 atoms C
[ 1 mol CO2 ] [ 1 molecule CO2]
b.
2.0 mol CO2 [ 6.02 x 1023 moleculesCO2] [ 2 atoms O ] = 2.4 x 1024 atoms O
[ 1 mol CO2 ] [ 1 molecule CO2]
c.
2.0 mol CO2 [ 6.02 x 1023 moleculesCO2] = 1.2 x 1024 molecules CO2
[ 1 mol CO2 ]
Text Heath
p.104 #4
please write all units and use conversion factors clearly!
4) 1.25 mol H2SO4 [ 6.02 x 10 23 molecules]= 7.53 x1023
[ 1. mol]
3B. particles à mol
How many mol of H2O in 2.5 x 1024 molecules of H2O
2.5 x 1024 molecules of H2O [1. mol H2O ] = 4.2 mol H2O
[ 6.02 x 10 23 molecules]
How many mol of H in 5.0 x 1024 atoms of H?
5.0 x 1024 atoms of H [ 1 mol H ] = 8.3 mol H
[ 6.02 x 1023 atoms]
c. How many mol of H in 5.0 x 1024 molecules of H2O?
5.0 x 1024 molecules of H2O [1 mol H2O ] [ 2 mol H ] = 1.7 x 101 mol H
[6.02 x1023 molecules H2O] [ 1 mol H2O]
Or….
5.0 x 1024 molecules of H2O [2 atoms H ] [ 1 mol H ] = 1.7 x 101 mol H
[1 molecule H2O] [ 6.02 x 1023 atoms]
Heath p. 104 Q.4-9
p. 109 Q.4,5,15
4A. gramàmolàparticles
4B. particlesà molà gram Heath p.109 Q. 16