Presentation on theme: "What is the Mole? Molar Mass"— Presentation transcript:
1 What is the Mole? Molar Mass Unit 5 – The MoleWhat is the Mole? Molar Mass
2 We count pieces in MOLES. How do we measure items?You can measure mass,or volumeor you can count pieces.We measure mass in grams.We measure volume in liters.We count pieces in MOLES.2
3 We’re not talking about this kind of mole! What is the mole?We’re not talking about this kind of mole!
4 A. What is the Mole? A large amount!!!! VERY A counting number (like a dozen)Avogadro’s number1 mol = 6.02 1023 itemsA large amount!!!!VERY
5 Similar Words for an amount Pair: 1 pair of shoelaces= 2 shoelacesDozen: 1 dozen oranges= 12 orangesGross: 1 gross of pencils= 144 pencilsReam: 1 ream of paper= 500 sheets of paper
6 Practice… If I have 1 mole of marshmallows, how many do I have? If I have 2 moles of jelly beans, how many do I have?If I have 6.02 x 1023 pennies, how many do I have?6.02 X 1023 Marshmallows2 moles x 1023 jelly beans1 mole= 1.2 x 1024 jelly beans1 mole of pennies
7 A. What is the Mole? HOW LARGE IS THE MOLE?? 1 mole of hockey pucks would equal the mass of the moon!1 mole of basketballs would fill a bag the size of the earth!1 mole of pennies would cover the Earth 1/4 mile deep!
8 Why do we need the mole?The mole is used as a mass comparison for any element in the periodic table.We can compare the mass in grams of any two elements only if they contain the same number of atoms.Remember 1 dozen Golf balls vs. 1 dozen marbles8
9 Why 6.02 x 1023 ? Where did this number come from? This is the number of atoms in exactly 12.0 grams of Carbon-12.This is the standard for the mole!It is a very large number, because atoms are so small!
10 Molar Mass – the mass in grams of one mole of atoms or molecules. Atomic Mass = the mass of one atom of any element in atomic mass units (amu).Molar Mass – the mass in grams of one mole of atoms or molecules.1 Sodium atom weighs – 23 amu’s1 mole of Na atoms weighs – grams
12 Molar MassMolar mass is the generic term for the mass of one mole of any substance(expressed in grams/mol)The same as:1) Gram Molecular Mass (for molecules) ) Gram Formula Mass (ionic compounds)3) Gram Atomic Mass (for elements)molar mass is just a much broader term than these other specific masses
13 Calculating Molar Mass for Compounds Molar mass is determined by the adding the weights of all the atoms in a compound.Calculate the formula mass of magnesium carbonate, MgCO3.24.3 g g x (16.00 g) =84.3 gThus, 84.3 grams is the formula mass for MgCO3.
14 Compound Molar Mass Examples watersodium chlorideH2O2(1.01) = g/molNaCl= g/mol