1. Write a balanced chemical equation for the reaction between solid zinc and solid sulfur. 2. What is the reaction type? Day

You do NOT have to write this one: Sit with your lab group from Friday and get out your lab handout! Day

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

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 # * = 1 mole The atomic mass = 1 mole Ca 20 Calcium 40.08

Avogadro’s # * = 1 mole Conversion Factors: * particles 1 mol * 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 * 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 Fe X g Fe 1 mol Fe = 1.5 * 10 1 mols Fe

820 g of oxygen (O) = _________ mols? 820 g O X g O 1 mol O = 5.1 * 10 1 mols 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 X 65.4 g Zn 1 mol Zn = 1.00 * mols Zn

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