1 / 13

U4 One Step Stoichiometry Problems

U4 One Step Stoichiometry Problems. Chemistry Ms. Boon 10.10-10.11. Catalyst. 7 days = 1 week. 10 weeks. X. 7 days 1 week. 70 days. =. Pick up the notes handout and answer the following question at the top of the page:

maja
Download Presentation

U4 One Step Stoichiometry Problems

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. U4 One Step Stoichiometry Problems Chemistry Ms. Boon 10.10-10.11

  2. Catalyst 7 days = 1 week 10 weeks X 7 days 1 week 70 days = Pick up the notes handout and answer the following question at the top of the page: 10 weeks have passed since the first day of school. How many days have passed? How do you know?

  3. Objective I can perform one-step stoichiometry conversions using a worksheet, notes, and a puzzle. I can show my work and use units in all my calculations.

  4. Mini Review: What is the mole? Think, Pair, Share: What is counting by weighing? Imagine you work at a candy store and a customer asks for 500 jelly beans. There is a long line and you do not want to count 500 beans. But you have a scale. What can you do? Answer: Find the weight of one bean. Then multiply by 500. Finally, measure this mass of beans and it should be 500 beans. The mole is a number we use to make counting atoms, ions, and molecules much easier. The mole allows scientists to count by weighing.

  5. Mini Review: What is the mole? • 1 mole = 6.02 x 1023particles. This does not change. • The number of particles in 1 mole is calledAvogadro’s number

  6. THE MOLE -- Why? • Why is the mole useful to us as chemists?? • Make a dot on your paper with your pencil. • Guess how many atoms of Carbon graphite are in that dot. • 25 million atoms in that tiny dot!

  7. Mini Review: What is the mole? Example 2: What is the molecular weight of baking soda? Hint: First find the mass of each element, then multiply by subscripts, then add up the answers. Example 1: What is the molar mass of aluminum? Hint: The molar mass is the same as the atomic mass, just add “g” for grams. Answer 26.98 g/mol AnswerNaHCO3 = 84 g/mol • Molar mass and molecular weight are the mass in gramsof one mole of an element or compound. • Different elements and compounds have differentmolar masses or molecular weights.

  8. Mini Review: What is the mole? Example 2: What is the molecular weight of baking soda? Hint: First find the mass of each element, then multiply by subscripts, then add up the answers. AnswerNaHCO3 = 84 g/mol 16 g x 3 48 g 1 g x 1 1 g 12 g x 1 12 g 23 g x 1 23 g = 84 g/mol + + + 5 minute - Quick Practice: Choose at least 2 molar mass/molecular weight problems from your worksheet.

  9. Stoichiometry Conversions Part 1: Grams to Moles and Moles to Grams. Ex 1: Moles to Grams. How many moles is 24 g of carbon? Ex 2: Grams to Moles. How many grams is 10 moles of Gold? Given: 24 g Unknown: # moles Conversion: 1 mol/12 g Set up: 24 g x 1 mol= 12 g Answer: 2 mol Given: 10 mol Unknown: # g Conversion: 197g/1 mol Set up: 10 molx 197 g = 1 mol Answer:1970 g 5 minute - Quick Practice: Choose at least 2 gram to mole or mole to gram problems from your worksheet. Calculating the molar mass or molecular weight of a chemical reveals the mass of one mole of that chemical. What if we are given more than one mole of a substance? Or some random amount in grams? Use the molar mass or molecular weight as a conversion factor to move between moles and grams.

  10. Stoichiometry Conversions Part 2: Particles to Moles and Moles to Particles. Ex 1: Particles to Moles. How many moles is 1.20 x 1024 atoms of carbon? Given: 1.20 x 1024 atoms Unknown: # moles Conversion: 1 mol/6.02 x 1023atoms Set up: 1.20 x 1024atoms x 1 mol= 6.02 x 1023atoms Answer: 2 mol Avogadro’s number allows us to determine the number of atoms, molecules, or ions (generally particles) in a given sample. Use 1 mole = 6.02 x 1023 as a conversion factor to move between moles and particles.

  11. Stoichiometry Conversions Part 2: Particles to Moles and Moles to Particles. Ex 2: Moles to Particles. How many atoms is 10 moles of Gold? Given: 10 mol Unknown: # atoms Conversion: 6.02 x 1023/1 mol Set up: 10 molx 6.02 x 1023atoms= 1 mol Answer:6.02 x 1024 atoms 5 minute - Quick Practice: Choose at least 2 particle conversion problems from your worksheet. Avogadro’s number allows us to determine the number of atoms, molecules, or ions (generally particles) in a given sample. Use 1 mole = 6.02 x 1023 as a conversion factor to move between moles and particles.

  12. Extra Special Bonus: Video Review – Super Hero Science How does the law of conservation of mass limit the size of a super hero? http://www.youtube.com/watch?v=fpV7DKwcqbk&list=PLJicmE8fK0EjcBM04Tz0UvUTJ3utyYD1G

  13. More Practice See textbook p. 224-233 Try the sample problems on p. 228 and 229

More Related