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Honors Molecular Formula

Honors Molecular Formula. Warm Up. The bond in fluorine has a length of 133pm. a . Draw the Lewis Structure. b. Convert to meters. c. Convert to nm. d. What is the shape and bond angle?. Questions on Mole Review WS?.

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Honors Molecular Formula

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  1. Honors Molecular Formula

  2. Warm Up • The bond in fluorine has a length of 133pm. a. Draw the Lewis Structure. b. Convert to meters. c. Convert to nm. d. What is the shape and bond angle?

  3. Questions on Mole Review WS? If you didn’t take the Bonding Test last week… they are in the testing center. You have ONE week (1/24) Or the score becomes a zero!

  4. Molecular Formula Activity- Do you need more time with this??? Get into groups of 3. Take turns leading the group through the questions. Write a list of new vocabulary terms in your CB.

  5. Finish the molecular formula activity! Take 15 minutes to finish the activity. Find another group that has the same empirical formula as your Lego molecule. (The match is worth points!) When you finish, work on the Formula packet… you know more than you think you know!

  6. Debrief Activity • What is the difference between an empirical formula and a molecular formula? • Do you have questions on the front side of the activity? • How did you find the total mass of your compound?

  7. More Debrief… 4. How did you calculate the percent composition of an element in a compound? Example: What is the percent composition of each element in sodium sulfate.

  8. More Debrief… • Were you able to find the bag containing empirical and molecular formulas that match? What can we say about the mass of a molecular formula compared to that of the empirical formula? Example: What is the molecular formula of a compound with a molar mass of 64.20 g/mol if the empirical formula is carbon tetrahydride (methane).

  9. Homework… You should be able to do … Pages 1 and 2- Determine the formula, calc % comp and answer the questions. Page 3- If you are having trouble with these…. Try page 4 (a little easier).

  10. Zinc Chloride Lab Do the prelab and read the background. Honestly…. Do we know the formula for zinc chloride? So, we really aren’t “determining” the formula as much as we are “confirming” the formula.

  11. Let’s talk about what is happening conceptually. • You are going to mass the zinc. When it undergoes a chemical reaction, will the mass of Zn change? • What does HCl look like when it is in aqueous solution? • Discuss the reaction Zn + HCl

  12. Science Choices

  13. Period 2 You have about 7 minutes to get into groups and look at your Mole Review WS to find silly mistakes. (Please start looking on the back side!) The average score on this assignment in periods 4 and 8 was a “5/10”.

  14. Warm Up- Friday You have a 250.0 g sample of nitrogen monoxide that undergoes a decomposition reaction. a. Determine the percent composition of each element. b. What is the mass of nitrogen? c. What is the mass of oxygen?

  15. What if we were given amounts of each element and asked to determine the formula. Example: A compound has 45.0g of oxygen, 22.6g of sulfur and 32.4g of sodium. What is the empirical formula. Remember- the formula compares the number of MOLES… so we need to look at moles! Assume 100.g

  16. Sometimes you don’t get a whole number ratio…Yikes An oxide of aluminum is formed by the reaction of 4.151g Al with 3.692g of Oxygen. Determine the empirical formula of the compound.

  17. Other questions that you’ve encountered on the packet?

  18. Finish the Zinc Chloride Lab I put the balances in the same locations that they were in on Wed… Why is that important? Sources of experimental error??? Work on the lab calculations as a group. No lone rangers… if you are strong, there may be someone in your group who needs you! Don’t rely on the smarty party in your group to do all the calculations… you would be amazed at how often they get things wrong.

  19. Let’s look at some of the analysis questions… Be sure to read the entire question and answer all parts of the question!

  20. Warm Up- Look at your zinc chloride lab… 1. Did you do the prelab questions? 2. Do your calculations have the correct number of significant figures? 3. Did your error analysis answers have complete sentences? 4. Did you write a conclusion without personal pronouns?

  21. Debrief the Lab

  22. Questions on HW packet? About 10 minutes

  23. Formula of a Hydrate Lab Inquiry Lab A Hydrate is a compound that contains water. The chemical state of the water varies… In ionic compounds Na2SO4·10H2O Name: Sodium sulfate decahydride Howwouldwecalculate the molar mass!

  24. An Anhydrate or Anhydrous Salt Is the ionic salt left when all the water has been driven off a hydrate.

  25. Hydrate Lab Purpose: To determine the molecular formula for the sample hydrate. CuSO4· __??_ H2O

  26. Honors- Design a lab that will allow you to determine the formula of the hydrate. Equipment available: Test tubes Test tube clamp Bunsen burner Scale Hot pad Scoopula Hot glove 100 ml beaker. Matches Copper (II) Sulfate hydrate- You can use 0.3g 10 minutes- • Write a procedure. • Design a data table that will help you collect all the data. • Discuss the calculations you will need to perform to complete the lab. • What safety concerns do you have?

  27. Your Lab Write Up- Due Monday! • Background- Find out more about hydrates and what is “trapping” or “attracting” the water. (Cite your resources) • Purpose- If, then, because statement • Procedure- Step by step, clearly written. • Materials List- Complete with correct spelling • Data- Preferably on a table • Analysis- Calculations (can hand write and scan) • Conclusion- What was learned (no personal pronouns). • Share with each other on Google Docs… 9. Turn it in to me through my website.

  28. Rothschildscience.com Formula/Reaction unit Let's take a look

  29. Here is a data table that might help you with your procedure Mass of empty test tube _____g Mass of test tube and Copper (II) Sulfate _____g Mass of Copper (II) Sulfate before heating _____ g Mass of Copper (II) Sulfate after heating _____ g Mass of water released during heating _____ g Remember you are finding the ratio of Copper (II) sulfate molecules to water molecules.

  30. Warm Up- Work on these in small groups for about 15 minutes. • What is the percent composition of water found in sodium sulfide nonhydride? Na2S · 9H2O • A 5.0g sampleofbariumchloridehydratewasheatedandonly 4.3g oftheanhydroussaltremained. Whatpercentwaterwas in thehydrate? • A 6.7g sample of Na2SO4·H2O isheated. Howmuchanhydroussaltremains? • A 5.0g sample of Cu(NO3)2· nH2O isheatedand 3.9 goftheanhydroussaltremains. Whatisthevalue for n?

  31. Questions on Packet? Turn them in!

  32. Go to Types of Reactions

  33. Combustion Analysis Problems Combustion reactions usually involve a hydrocarbon and oxygen as the reactants and produce carbon dioxide, water and energy. Write the chemical equation—

  34. Combustion Analysis Problems If we can measure the amount of products released in the combustion reaction… we can figure out the empirical formula for the hydrocarbon.

  35. Combustion Analysis Problems What is the empirical formula for the hydrocarbon that produces: 23.118 g CO2 18.930 g H2O C?H?

  36. Work on the WS

  37. Warm Up Consider the formula NaNO3 a. Draw the Lewis structures for Na and NO3. b. Label the cation and anion… do you see why they want to gain and lose electrons? c. Name the compound

  38. Combustion Analysis WS • CH2 • CH • C3H7 • C2H3 Questions??

  39. I have, Who Has

  40. Work on the Review

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