110 likes | 214 Views
Convert 3 miles into inches (5280 ft = 1 mile) How many donuts are in 6.7 dozen donuts? Use dimensional analysis. If one ream of paper is 500 sheets, how many sheets are in 3.4 reams of paper. Daily science (pg 72). The Mole. Pg. 71. A way to group atoms together
E N D
Convert 3 miles into inches (5280 ft = 1 mile) • How many donuts are in 6.7 dozen donuts? Use dimensional analysis. • If one ream of paper is 500 sheets, how many sheets are in 3.4 reams of paper. Daily science (pg 72)
The Mole Pg. 71
A way to group atoms together • 12 is to a dozen as 6.02 x 1023 is to a mole • Avogardo’s number = 6.0221367 x 1023 • Based off of number of carbon atoms in 12 g of carbon -12 • 602000000000000000000000 atoms in one mole • Can be used to count: molecules, atoms, compounds Definition of a Mole
Can write a conversion factor using Avogadro’s number to convert from moles to particles or particles to moles • Moles to particles: x 6.02 x 1023 1 mol • Particles to moles: x 1 mol 6.02 x 1023 Converting moles
Determine the number of atoms in 2.50 moles of Zn • Calculate the number of molecules of H2O in 11.5 moles. • How many moles is 5.75 x 1024 atoms of Al? • How many moles is in 3.58 x 1023 units of ZnCl2 Examples
Moles of different substances have different masses • Called molar mass (mass in grams of one mole of a substance) • Units: g/mol Mass and the Mole
What is the molar mass of Silicon? • What is the molar mass of Cl2? • What is the molar mass of H2O Examples
To find the mass of a certain amount of a substance, use a conversion factor for molar mass • Mass to moles: x 1 mole molar mass • Moles to mass: x molar mass 1 mole Conversions using molar mass
How many moles are in the following: • 25.5 g of Ag • 300.0 g S • What is the mass of the following amount of moles: • 3.45 mol of Co • 42.6 mol Si Examples
Multi step problem • Combine both conversion factors • Mass to atoms: x1 mol x 6.02 x 1023 atom molar mass 1 mol • Atoms to mass: x 1 mol x molar mass 6.02 x 10231 mol Conversions from mass to atoms and atoms to mass
Convert 3.40 x 1022 atoms of He into grams • Convert 1.00 x 1024 molecules of MgO into grams • Convert 55.2 g Li into atoms Examples