140 likes | 259 Views
Molar Relationships. Dozen = 12. Pair = 2. Names associated with an amount. Can you think of any more?????. The Mole…. The mole (mol) is the amount of a substance that contains as many elementary entities as there are atoms in exactly 12.00 grams of 12 C.
E N D
Dozen = 12 Pair = 2 Names associated with an amount Can you think of any more?????
The Mole….. The mole (mol) is the amount of a substance that contains as many elementary entities as there are atoms in exactly 12.00 grams of 12C 1 mol = NA = 6.0221367 x 1023 Avogadro’s number (NA)
What is the mass of one mole of: S C Hg Cu Fe 3.2
Molar Mass • The Mass of 1 mole (in grams) • Equal to the numerical value of the average atomic mass (get from periodic table) 1 mole of C atoms = 1 mole of Cu atoms = 1 mole of S atoms = 1mole of Hg atoms = 1 mole of Fe atoms =
Learning Check! Find the molar mass (usually we round to the tenths place) = 79.9 g/mole • 1 mole of Br atoms • 1 mole of Sn atoms = 118.7 g/mole
1S 32.07 amu 2O + 2 x 16.00 amu SO2 SO2 64.07 amu Molecular mass (or molecular weight) is the sum of the atomic masses (in amu) in a molecule. For any molecule molecular mass (amu) = molar mass (grams) 1 molecule SO2 = 64.07 amu 1 mole SO2 = 64.07 g SO2 Let’s try some more…………….. 3.3
Molar Mass of Molecules and Compounds Mass in grams of 1 mole equal numerically to the sum of the atomic masses 1 mole of CaCl2 = 111.1 g/mol 1 mole Ca x 40.1 g/mol + 2 moles Cl x 35.5 g/mol = 111.1 g/mol CaCl2 Practice with this one: 1 mole of N2O4=
Learning Check! • Molar Mass of K2O = ? Grams/mole B. MolarMass of antacid Al(OH)3 = ? Grams/mole
Learning Check Prozac, C17H18F3NO, is a widely used antidepressant that inhibits the uptake of serotonin by the brain. Find its molar mass.
So, if one mole = the formula mass how do we calculate…. The mass of 05 mol of Calcium Carbonate The mass of 2.25 mol of Sodium Chloride
How many moles are there in? 100 g of Magnesium Hydroxide ? 64 g of Oxygen ?
Converting to # of atoms or molecules How many atoms are in 3.00 moles of Iron? How many atoms are in 0.25 moles of Water?
Molar Mass The molar mass of a compound is found by adding Together the molar masses of all of its elements, taking Into account the number of moles of each element present. Homework: pg 157 # 5-11