1. Write a balanced chemical equation for the reaction between solid zinc and solid sulfur.

2. What is the reaction type?

Day 4 9-26

You do NOT have to write this one:

Sit with your lab group from Friday and get out your lab handout!

Day 5 9-29

Lab Reports are due Wednesday 10-1

Monday 9-29 for bonus

You do NOT have to write this one:

Sit with your lab group from Friday and get out your lab handout!

Day 6 9-30

Lab Reports are due Wednesday 10-1

Monday 9-29 for bonus

CORRECT AMOUNT = 3.21 grams

1/10 the molar mass of Zn reacts with 1/10 of the molar mass of S

So why is it 1/10 for 1/10? Why not 1/10 for 2/10 or 3/10?

And where’d the masses come from?

The key came from a combination of the atomic masses and the chemical equation:

Zn + S ZnS

For every one “piece” of Zn we need one “piece” of S to form one “piece of ZnS

1/10 for 1/10

So where’d the masses come from?

So what was the key?

A mole is like a dozen, BUT better, How?

A mole is a counter like a dozen, but it also relates to mass!!!

Avogadro’s #

6.022 * 1023 = 1 mole

The atomic mass

= 1 moleCa20

Calcium

40.08

Avogadro’s #

6.022 * 1023 = 1 mole

Conversion Factors:

6.022 * 1023 particles

1 mol

1 mol

6.022 * 1023 particles

Molar Mass – the mass of one mole of the substance is its molar mass (g/mol) = atomic mass of the element

- The molar mass of an element contains 1 mole of atoms (6.022 * 1023 atoms)

So …

We can convert from grams to moles to atoms and back and forth and everything in between

We have a new kind of conversion: If you know grams of some

to moles using the molar mass on the periodic table:

substance you can convert

820 g of Iron (Fe) = __________ mols?

820 g of Iron (Fe) = __________ mols?

820 g Fe X55.847 g Fe

1 mol Fe=

1.5 * 101 m

ols Fe

820 g of oxygen (O) = _________ mols?

820 g O X15.999 g O

1 mol O=

5.1 * 101 m

ols O

If mols count atoms, What can we tell about the atoms of Fe compared to the atoms of O???

= Masses

- More Oxygen atoms

Therefore Iron atoms Must be bigger

6.54 g of Zinc = __________ mols?

6.54 g Zn X65.4 g Zn

1 mol Zn =

1.00 * 10-1 mols Zn

Read + review section 10.1 (pages 306-315) AND complete #s 9-15 due on Thursday 10-2