advertisement

Introduction to the Mole Please Return! Directions: Do activity in your notebook, please do not write on this paper, but put all answer in your notebook. Read Ch 3.3 pg 82-84 Purpose: To discover a method of counting “things” that you are not able to see. Intro: 1. When you buy eggs you usually ask for a _____ eggs. You know that one dozen of any item is _____. 2. Paper is not packaged by the dozen. Paper is packaged by a ream. A ream of paper has 500 sheets. Why is it useful to use units like a dozen or a ream? _________________________________ 3. What determines how many items should make up a particular unit? _____________________ 4. If you were asked to design a new unit to count something, what would you consider when choosing how many items should be included in your new counting unit? 5. Data: How many items in each picture: Item Number mice Candles books Question marks ANALYSIS AND INTERPRETATION 6. As you know, a dozen represents 12 items. Since I did not have enough items to make a dozen, I decided to make a new counting unit. I called this unit an OWL. Each of the pictures contains _____ items. We will call this number of items an OWL. If you understand the concept of OWL as a counting unit, just like a dozen for counting by 12, you should be able to complete the following questions. Questions 7. An OWL of oranges will have _____ oranges. 8. An OWL of pretzels has ____ pretzels. An OWL of desks has _____ desks. 9. An OWL of molecules of water has ____ molecules of water. 10. An OWL of particles has ___ particles. 11. An OWL of atoms of iron has _____ atoms of iron. 12. An OWL of formula units of salt has _______ formula units of salt. Now that you understand the meaning of an OWL, you should be able to answer the following: 13. How many Hershey’s Kisses are in 2 OWLS? _______ 14. How many caramels are in 10 OWLS? _______ 15. How many Hershey’s Kisses are in 400 OWLS? _______ 16. How many caramels are in 1/2 OWL? _____ 17. WRITE DIRECTIONS FOR FINDING THE # OF ITEMS IF GIVEN THE # OF OWLS. 18. How many pencils are in 20 OWLS? _______ 19. How many oranges are in 5 OWLS? _______ 20. How many pencils are in 0.5 OWLS? _______ 21. How many pencils are in 0.25 (1/4) OWLS? _______ 22. How many atoms of silver are in 20 OWLS? _______ 23. How many molecules of water are in 10 OWLS? _______ Finding the Number of OWLS If you are given the number of items you can tell the number of OWLS. For example, since one OWL is 4 items, 8 items make up 2 OWLS. 24. 25. 26. 27. 28. 29. How many OWLS are 16 Hershey’s Kisses? ______ How many OWLS are 100 pretzels? ____ How many OWLS are 400 desks? ____ How many OWLS is 1 orange? ________ (Write a fraction or a decimal.) How many OWLS are 2 caramels? _________ Write directions for finding the number of OWLS if given the number of pieces. 30. How many OWLS are 48 Hershey’s Kisses? ______ 31. How many OWLS are 2 Hershey’s Kisses? ______ The Mole: As you can imagine, an OWL of molecules of water would be too small to see. Scientists had toselect a bigger unit for counting molecules of substances. The unit scientists use is called a MOLE. One MOLE of anything has 602,200,000,000,000,000,000,000 items. This number is called AVOGADRO’S NUMBER and is usually written in scientific notation as 6.022 x 1023 One MOLE of anything has 6.022 x 1023 items. Use the rules you have written for calculations involving OWLS to answer questions about MOLES. Remember to use 6.022 x 1023 for the number of items in a MOLE. Recall how to multiply numbers written in scientific notation. (see bottom on page) [4 x 6.022 x 1023 : (6.022 x4)x1023 = 24.08 x 1023 = 2.408 x 1024]. Note: Atoms and molecules in these questions are words meaning items. 32. 33. 34. 35. 36. 37. 38. 39. 40. How many Hershey’s Kisses make up 1 MOLE? _______ How many caramels make up 10 MOLES? _______ Find the number of atoms of sodium in 2 MOLES. _______ Find the number of molecules of water in 6 MOLES. _______ Find the number of caramels in 0.5 MOLES. ________ How many moles of caramels are 6.022x1023 of caramels? _______ How many moles of desks are 6.022x1023 of desks? ______ How many moles of pens are 12.04x1023 of pens? ______ How many moles of sodium atoms are 12.04x1023 of sodium atoms? _______ Reminder: One MOLE has 6.022 * 1023 items or there are 6.022 * 1023 items/mole. Items may mean: caramels, Hershey’s Kisses, bananas, oranges, ATOMS, FORMULA UNITS, MOLECULES, IONS, etc. 41. 42. 43. 44. 45. 46. 47. 48. 49. 50. How many atoms of potassium make up one MOLE ? _____ How many atoms of potassium make up 2 MOLES? _____ How many formula units of salt make up 10 MOLES? _____ How many molecules of water make up 1 MOLE? _____ How many molecules of water make up 5 MOLES? _____ How many moles are 6.022 x 1023 atoms of sodium? _____ How many moles are 12.04 x 1023 atoms of carbon? _____ How many moles are 18.06 x 1023 atoms of sodium? _____ How many moles are 60.22 x 1023 atoms of sodium? _____ How many moles are 6.022 x 1023 molecules of water? _____