Slide 1

Slide 2

1. What is a mass spectrometer and how does it work? 2. What kind of ion is produced to create a mass spectrum? 3. What is a mass spectrum? End

Slide 3

Havent you always wanted to know whats actually going into your body? Naming Practice Stations practice Naming big molecules Naming little molecules Naming organic molecules Naming inorganic molecules Name it all!

Slide 4

Slide 5

Slide 6

Slide 7

Slide 8

Slide 9

LT 2.11 I can explain the concept of the mole and why it is an adequate means by which to express the amount of given substance. LT 2.12 I can determine the empirical and molecular formula for any compound given its constituent parts. I can also calculate percent composition for each element in that compound.

Slide 10

Slide 11

Recall that Avogadro proposed that 1 mole = 6.022 x 10 23 particles. If you have 1 mole this means you have 6.022 x 10 23 of this substance. This works because particles are really small!

Slide 12

One mole of Carbon- 12 holds 6.022 x 10 23 particles. This can be applied to any substance and always has the same number of particles. This isotope was easier to use than Carbon-13 or C-14.

Slide 13

We can convert between the amount of a substance to moles by using the molar mass. To do this, use the atomic mass on the periodic table.

Slide 14

You have 5.380 g of C 6 H 12 O 6, how many moles do you have?

Slide 15

Slide 16

Percent composition - is the percent by mass of each element present in a compound. How much of one thing is in another?

Slide 17

Water, H2O is a great example. One mole of water is 18.0152 grams In that compound there are two moles of H atoms and 1 mole of O atoms.

Slide 18

Calculate the percent by weight of sodium (Na) and chlorine (Cl) in sodium chloride (NaCl) molecule.

Slide 19

Slide 20

Molecular Formula is what the actual molecule is! Molecular Formula - a formula giving the number of atoms of each of the elements present in one molecule of a specific compound.

Slide 21

Empirical means observed, or determined from experimentation! Empirical formula is the smallest whole number ratio of moles of each element in a compound. CaCl 2 --> there is 1 mole of calcium for every 2 moles of chlorine

Slide 22

1. If you have masses go onto step 2. If you have %. Assume the mass to be 100g, so the % becomes grams. 2. Determine the moles of each element. 3. Determine the mole ratio by dividing each elements number of moles by the smallest value from step 2. 4. Double, triple to get an integer if they are not all whole numbers

Slide 23

Turn each of the molecular formulas to the right into empirical formulas.

Slide 24

The atomic weight of element X is 100. g/mol. 50.0 grams of X combines with 32.0 g of oxygen. What is the simplest formula for the resulting compound? The atomic weight of oxygen = 16.0 g/mol.

Slide 25

Which of the following substances has an empirical formula that is different from that of the others? (a) Erythrose: C 4 H 8 O 4 (b) Propionic acid: C 3 H 6 O 2 (c) Acetic acid C 2 H 4 O 2 (d) Glucose C 6 H 12 O 6

Slide 26

KHAN YOU DO IT? http://www.khanacademy.org/test- prep/mcat/physical- processes/stoichiometry/v/molecular-and- empirical-formulas http://www.khanacademy.org/test- prep/mcat/physical- processes/stoichiometry/v/molecular-and- empirical-formulas Watch video and answer Qs

Slide 27

Slide 28

Slide 29

Slide 30

Complete the stations review independently or with your table.

Slide 31

Slide 32

Quantitative on Ch. 2 on Monday Answers to practices