1. How many atoms are in 6.5 moles of zinc? 1 mole = atomic mass (g) 6.5 moles 6.02 x 1023 atoms = 3.9 x 1024 atoms 1 mole 2. How many moles of argon are in a sample containing 2.4 x 1024 atoms of argon? 2.4 x 1024 atoms of argon 1 mole 6.02 x 1023 atoms 3. How many moles are in 2.5g of lithium? 2.5 grams Li 1 mole 6.9 g 4. Findthemassof4.8molesofiron. 4.8 moles 55.8 g 1 mole = 4.0 mol = 0.36 mol = 267.84 g = 270g
1 mole = 6.02 x 1023 atoms 1 mole = atomic mass (g) MASS (g) 1 mole = molar mass (look it up on the PT!) MOLE 1 mole = 6.02 x 1023 atoms PARTICLES (ATOM) Two Step Problems: 1. What is the mass of 2.25 x 1025 atoms of lead? 2.25 x 1025 atoms of lead 1 mole 207.2g = 6.02 x 1023 atoms 1 mole 2. How many atoms are in 10.0g of gold? 10 g gold 1 mole 6.02 x 1023 atoms = 197.0g 1 mole PRACTICE PROBLEMS: 1. How many moles are equal to 625g of copper? 625g of copper 1 mol = 9.77 mol Cu 64 g Cu 7744.19g = 7740g 3.06 x 1022 atoms 2. How many moles of barium are in a sample containing 4.25 x 1026 atoms of barium? 4.25 x 1026 atoms of barium 1 mol = 706 mol 6.02 x 1023 atoms 3. Convert 2.35 moles of carbon to atoms. 2.35 moles 6.02 x 1023 atoms = 1.41 x 1024 atoms 1 mole 4. How many atoms are in 4.0g of potassium? 4.0 g 1 mole 6.02 x 1023 atoms = 6.2 x 1022 atoms 39.1 g 1 mole
1 mole = 6.02 x 1023 atoms 1 mole = atomic mass (g) 5. Convert 9500g of iron to number of atoms in the sample. 9500 g Fe 1 mole 6.02 x 1023 atoms = 55.8g 1 mole 6. What is the mass of 0.250 moles of aluminum? 0.250 moles 27.0g = 6.75 g Al 1 mole 7. How many grams is equal to 3.48 x 1022 atoms of tin? 3.48 x 1022 atoms 1 mole 118.7g 6.02 x 1023 atoms 1 mole 8. What is the mass of 4.48 x 1021 atoms of magnesium? 4.48 x 1021 atoms 1 mole 24.3g 6.02 x 1023 atoms 1 mole 9. Howmanymolesis2.50kgoflead? 2.50kg 1000 g 1 mol 1 kg 207.2 g 1.0 x 1026 atoms = 6.86 g Sn = 0.181 g Mg or 1.8 x 10-1 = 12.1 mol 10.Find the mass, in cg, of 3.25 x 1021 atoms of lithium. 3.25 x 1021 atoms 1 mol 6.9g 100cg 6.02 x 1023 atoms 1 mol 1 g = 3.7 cg
