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Mass and moles. B. Molar Mass. The mass of 1 mole of atoms Isotopes have different masses so the periodic table is an average. That’s why they have decimals. Atomic mass tells the... atomic mass units per atom (amu) grams per mole (g/mol) Round to 2 decimal places.
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B. Molar Mass • The mass of 1 mole of atoms • Isotopes have different masses so the periodic table is an average. • That’s why they have decimals. • Atomic mass tells the... • atomic mass units per atom (amu) • grams per mole (g/mol) • Round to 2 decimal places
B. Molar Mass Examples 12.01 g/mol 26.98 g/mol 65.39 g/mol • carbon • aluminum • zinc
B. Molar Mass • Mass of 1 mole of an element or compound. • Molar mass = 1 mole = 6.02 x 1023 atoms • So, how many atoms are in 12g of carbon and 16g of oxygen?
C. Molar Conversion Examples • How many moles of carbon are in 26 g of carbon? 26 g C 1 mol C 12.01 g C = 2.2 mol C
C. Molar Conversion Examples • How many grams of Sodium are present in 2.8 mol Sodium? 2.8 mol Na 22.99 g Na 1 mol Na =64 g Na
Practice • How many grams are in 4.60 moles of magnesium? • How many moles are in 273.6 grams of nitrogen? • How many atoms are in 43.0 grams of aluminum? • How many grams are in 8.36 x 1023 atoms of carbon? 112 g Mg 19.53 moles N 9.59 x 1023atoms Al 16.7 grams C
Practice • How many atoms are in 43.0 grams of aluminum? • How many grams are in 8.36 x 1023 atoms of carbon? 9.59 x 1023atoms Al 16.7 grams C
Homework Tonight Determine if you are using grams or atoms. 1 mole = 6.02 X 1023 atoms or molecules 1 mole = # grams from periodic table Warning! You MAY need to use BOTH! Follow your units...they will show you the way