Show:
The Mole
Conversions
Empirical Formulas
Molecular Formulas
Percent composition
100
What is the numerical value for a mole?
6.02 x 10^23
100
What is the molar mass of water?
17.99g
100
What is an empirical formula?
the atoms of a molecular formula shown in the smallest ratio
100
What is a molecular formula?
the chemical formula with atoms in the ratios they actually occur
100

What percentage of methane (CH4) is carbon?

What is 75%

200
What element was the mole derived from?
carbon-12 (the number of atoms in 12g of carbon-12)
200
How many moles are there in 76.44 g H3PO4?
0.78 mol
200
What is the empirical formula for carbon monoxide?
CO
200
What is the molecular formula for copper II sulfate?
CuSO4
200

What percentage of water is hydrogen?

What is 11%

300
Which scientist is responsible for our use of the mole?
Avagadro
300
How many grams are in 6.2 mol BF3?
420.36g
300
What is the empirical formula for glucose? (C6H12O6)
CH2O
300
What are the steps you must follow to find the molecular formula?
find the empirical formula (using the "rhyming steps") calculate the empirical formula mass divide the molar mass by the empirical formula mass multiply the empirical formula by this number
300

What percentage of ammonium sulfite is nitrogen?

24%

400
Name 3 "representative particles" the mole can be used to count.
atoms, molecules, formula units, ions
400
How many representative particles are in 35.4 mol CO2?
2.13x10^25 molecules
400
What is the rhyme to help you remember the steps to finding the empirical formula?
percent to mass mass to mole divide by small multiply by whole
400
Find the molecular formula for a compound whose molar mass is 124.06 and empirical formula is CH2O3.
C3H4O2
400

If a bowl of Lucky Charms contains 10 grams cereal and 5 grams marshmallows, what percent is cereal?  

67%

500
Why do we use the mole in chemistry?
it is used as a counting unit because individual atoms or molecules are far too small to work with by themselves
500
Why can't you convert directly from particles to grams(and vice versa)?
You have to convert to moles first
500
What is the empirical formula for a compound containing 50.0% C, 5.5% H, and 44.4% O?
C3H4O2
500
What is the empirical formula of a compound containing 65.0% Cr and 35.0%O?
Cr4O7
500

A typical canister of table salt holds 737 grams. How many grams of that container are sodium? 

287.4g