Chemistry I Mole Review
What is a Mole? 1 mole = 6.02 x 1023 particles = molar mass = 22.4 L Mole = amount of substance that contains as many atoms/molecules/particles as there are atoms in exactly 12 g of carbon-12 isotope! Avogadro’s number = 6.02 x 1023
Molar Mass Mass of 1 mole of units (atoms or molecules) Number from the periodic table: Na: 22.9 C12H22O12: 358 g Fe2(SO4)3: 399.9 g CuSO4·5 H2O: mass + 5(mass) CuSO4: 159.7 g H2O: 18 g 159.7g + 5(18) = 249.7 g
Practice How many moles of methane (CH4) are in 6.07 g of methane?
Practice How many grams of Zn are in 0.356 mol of Zn? 23.3 g
Example How many molecules are in 0.65 mol of SO2?
Example How many atoms are in 16.3 g of sulfur? 3.06 E 23 atoms
Example What is the mass of 1 atom of Sn?
Example How many H grams are in 25.6 mol of urea [(NH2)2CO]? The molar mass is 60.06 g. 1. Convert from moles to grams of urea. 25.6 mol x (60 g / 1 mol) = 1536 g urea 2. Find ratio of H: urea using molar mass 4 : 60.06 = 0.46 mol H 3. Convert from grams of urea to grams of hydrogen. 0.46 mol x (1536 g / 1 mol) = 716.8 g