The Mole Measurement of Matter Measuring Matter How

The Mole Measurement of Matter

Measuring Matter • How do we measure matter? • Count, Mass, or Volume • • • Counting: 1 dozen apples = 12 apples Mass: 1 dz. Apples = 2. 0 kg apples Volume: 1 dz. Apples = 0. 20 bushels apples

Unit Conversions • Relating to a dozen allows you to convert between the units • Unit Conversion Factors

What is the Mole? • A counting number (like a dozen) • Avogadro’s number (NA) • 1 mol = 6. 02 1023 items

Size of Moles • 1 mole of pennies would cover the Earth 1/4 mile deep! n 1 mole of hockey pucks would equal the mass of the moon! n 1 mole of basketballs would fill a bag the size of the earth!

Molar Mass • Mass of 1 mole of an element or compound. • Atomic mass tells the. . . • atomic mass units per atom (amu) • grams per mole (g/mol)

Molar Mass Examples • carbon 12. 01 g/mol • aluminum 26. 98 g/mol • zinc 65. 39 g/mol

Molar Mass Examples • water · H 2 O · 2(1. 01) + 16. 00 = 18. 02 g/mol • sodium chloride · Na. Cl · 22. 99 + 35. 45 = 58. 44 g/mol

Molar Mass Examples • sodium bicarbonate · Na. HCO 3 · 22. 99 + 1. 01 + 12. 01 + 3(16. 00) • sucrose = 84. 01 g/mol · C 12 H 22 O 11 · 12(12. 01) + 22(1. 01) + 11(16. 00) = 342. 34 g/mol

Molar Conversions molar mass 6. 02 1023 MASS NUMBER MOLES IN GRAMS OF PARTICLES (g/mol) (particles/mol)

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

Molar Conversion Examples • How many molecules are in 2. 50 moles of C 12 H 22 O 11? 6. 02 1023 2. 50 molecules 1 mol = 1. 51 1024 molecules C 12 H 22 O 11

Molar Conversion Examples • Find the mass of 2. 1 1024 molecules of Na. HCO 3. 2. 1 1024 molecules 1 mol 84. 01 g 6. 02 1023 1 molecules = 290 g Na. HCO 3

The Mole and Avogadro’s Number • Mole: unit for defining a group of atoms • Avogadro’s number = 6. 022 x 1023 • 1 mole of atoms = 6. 022 x 1023 atoms • Molar mass - The mass (g) of 1 mole of atoms • What is the molar mass of carbon? 12. 01 g/mol C • One mole of any element contains the same number of atoms, 6. 022 x 1023, Avogadro’s number

Practice Calculations 1. Calculate the number of atoms in 1. 7 moles of boron. 2. Find the mass in grams of 2. 5 mol Na (sodium). 3. Calculate the number of atoms in 5. 0 g aluminum. 4. Calculate the mass of 5, 000 atoms of Au (gold)