The Mole
What is the molar mass of water?
18.0g
What is an empirical formula?
the atoms of a molecular formula shown in the smallest ratio
What is a molecular formula?
the chemical formula with atoms in the ratios they actually occur
What is a hydrate?
a salt with water bonded to the ions in the crystal structure
What element was the mole derived from -which is the basis for chemistry in general?
carbon-12 (the number of atoms in 12g of carbon-12)
How many moles are there in 76.44 g H3PO4?
0.78 mol
What is the empirical formula for carbon monoxide?
CO
What is the molecular formula for copper II sulfate?
CuSO4
What is the name for BaCl2•7H2O
barium chloride heptahydrate
How many liters are in 6.2 mol Cl2?
138.88 liters
What is the empirical formula for glucose? (C6H12O6)
CH2O
What are the steps you must follow to find the molecular formula?
find the empirical formula and calculate the empirical formula mass
divide the molar mass by the empirical formula mass
multiply the empirical formula by this number
What is the name for FeSO4•6H2O?
iron II sulfate hexahydrate
Name 3 "representative particles" the mole can be used to count.
atoms, molecules, formula units, ions, particles
How many representative particles are in 35.4 mol CO2?
2.13x10^25 molecules
What are the steps to finding the empirical formula?
percent to mass
mass to mole
divide by smallest mole
multiply if not whole numbers
Find the molecular formula for a compound whose molar mass is 124.06 and empirical formula is CH2O3.
C2H4O6
The term for a substance that has had the water removed
anhydrous
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
Why can't you convert directly from particles to grams(and vice versa) - what must the conversion be converted to first?
You have to convert to moles first
What is the empirical formula for a compound containing 50.0% C, 5.5% H, and 44.4% O?
C3H4O2
What is the molecular formula with 960 grams of a compound containing 65.0% Cr and 35.0%O?
Cr12O21
A 15.67 g sample of a hydrate of magnesium carbonate was heated to drive off the water. The mass was reduced to 7.58 g. What is the formula of the hydrate?
MgCO3 · 5H2O