1 / 21

CHEMISTRY

CHEMISTRY. Feb 22, 2011. Warm Up. Find the molar mass of these substances Fe 3 N 2 Mg(OH) 2. Agenda. Warm Up Unit 8 Notes Intro to Moles and Stoichiometry Practice Problems Homework Unit 8 Worksheet 1 Reminder: Test Make Up Wednesday, Thursday, or Friday ONLY. Are these moles?.

jennelle
Download Presentation

CHEMISTRY

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. CHEMISTRY Feb 22, 2011

  2. Warm Up • Find the molar mass of these substances • Fe3N2 • Mg(OH)2

  3. Agenda • Warm Up • Unit 8 Notes • Intro to Moles and Stoichiometry • Practice Problems • Homework • Unit 8 Worksheet 1 • Reminder: • Test Make Up • Wednesday, Thursday, or Friday ONLY

  4. Are these moles?

  5. What is a mole? • A unit of measurement • Since the numbers in chemistry are so small, we use a “preferred unit of measurement” (mole) to represent the small number

  6. What are the units of measurement? • "that equal number" of atoms randomly chosen. • the number of atoms in the atomic weight in g of any element. • the number of atoms in 16 g of oxygen, in 4 grams of He, in 32 g of sulfur, etc. • the number of molecules in the molecular weight, in grams, of any compound. • the number of molecules in 18 g of water, in 40 g of lithium carbide. • Much later, a mole, that equal number, was found to be 6.022 x 1023(representative particles).

  7. Examples • 1 mole (or abbr. mol) = 12.011 g of Carbon • 1 mol of Carbon = 6.02 x 1023 atoms of C • 1 mol of H2O = 6.02 x 1023 molecules of water • 1 mol of NaCl = 6.02 x 1023 units of NaCl

  8. Moles in mass • 1 mole can equal the atomic weight of an element. • 1mol of C = 12.011g of C • 1 mole can equal the atomic weight of a compound • 1mol of CO = 12.011g of C + 15.99 g of O = 28.0 g of CO

  9. Practice Problems • How many grams of Cu are in 1.20 mol of Cu? • How many moles are in 70g of Cl?

  10. Moles in compounds Let’s say you have water aka. H2O How many moles of Hydrogen atoms(ions) are in water? • Ask yourself how many individual atoms of Hydrogen do you see in water? • Did you say 2??? • Is that your final answer? • You are correct! So how many mols of Oxygen atoms do you see?

  11. Moles in an equation 2 H2 + O2 2H2O How many moles of Hydrogen molecules are in the reactants? *Coefficients serve as the number of moles too! Therefore, there are 4 mols of Hydrogen gas NOPE!!!! Fooled you.. 2 mols of Hydrogen gas

  12. Moles of atoms Volume of Gas at STP Representative Particles Representative Particles 1 mole 1 mole Mole Mole 1 mole 1 mole mol of atom 22.4 L 23 23 6.02x10 6.02x10 atomic atomic mol of atom 22.4 L 1 mole 1 mole 1 mole 1 mole mass mass 23 23 atomic atomic 1 mole 1 mole 6.02x10 6.02x10 mass mass 1 mole 1 mole Mass Mass Molecules Atoms Units Mole Conversion Boomerang

  13. Mole Conversions • Mass to mole or vice versa: • How many moles are in 24 g of Carbon? • Look at the boomerang: • Start with the given: 24 g (mass) of C • What do you want in the end? Moles of C • Use the conversion factor given: • 1 mole Atomic mass 24 g of C x 1 mol of C = 2.0 mol of Carbon 12.011 g of C

  14. White Boards • Given 200 g of water, how many mols of water do you have? • How many grams of carbon monoxide are in 1.5 mols of carbon monoxide?

  15. More conversion • Mole to atoms/molecules/particles or vice versa • How many atoms are in 2.00 mols of Carbon? • Look at the boomerang: • Where do you begin? (the given: mols) • What do you need in the end? (atoms: particles) • What’s the conversion factor? • 6.02 x 1023 Atoms of C 1 Mols of C 2.00 mols of C x 6.02 x 1023 atoms of C = 1.20 x 1024 atoms C 1 mol of C

  16. White boards • How many molecules of oxygen gas are in 3.0 mols of Oxygen gas? • How many mols of Oxygen gas are in 4.67 x 1024 molecules of Oxygen gas?

  17. More conversion • Mole to volume of gas or vice versa • What is the volume occupied by 2 mols of hydrogen gas? • Look at the boomerang: • Where do you begin? (the given: mols) • What do you need in the end? (volume of gas) • What’s the conversion factor? • 22.4 L of H2 1 Mols of H2 2.00 mols of H2 x 22.4 L of H2 = 44.8 L of H2 1 mol of H2

  18. White boards • Convert 4.38 moles of He to liters • Convert 3.01 L of N to moles

  19. Practice • Must show work (dimensional analysis) • How many grams are in 1 mol of Mercury? • Given a 1.5 mols of carbon dioxide, how many molecules of carbon dioxide do you have?

  20. Homework • Mole Conversion Worksheet 1

More Related