1. Honors Chem The Mole Unit 6 Mole- SI unit for amount of matter Mole- SI unit for amount of matter  mol  6.02 X 10 23 representative particles= Avogadro’s Number  You have to know which type of particle to pick Atom (Fe, C)Atom (Fe, C) Molecule (molecular compounds; CH 4 )Molecule (molecular compounds; CH 4 ) Formula Units (salts, ionic compounds; NaCl)Formula Units (salts, ionic compounds; NaCl) Ions (Na+)Ions (Na+)

2. Be able to convert from moles to particles: Be able to convert from moles to particles:  Multiply by: 6.02 X 10 23 particles 1mol How many molecules are in 0.360 mol of water?

3. Be able to convert from particles to moles: Be able to convert from particles to moles:  Multiply by: 1 mol 1 mol 6.02 X 10 23 particles  How many moles of Mg are in 1.25 X10 23 atoms?

4. Can also find the number of atoms in mol Can also find the number of atoms in mol  1. Convert moles to particles 6.02 X 10 23 particles 1mol 2. Convert molecules to atoms: # atoms 1 molecule (particle)  How many atoms are in 2.12 mol of C 3 H 8 ?

5. Ex. How many moles are in 4.65 X 10 24 molecules of NO 2 ? Ex. How many moles are in 4.65 X 10 24 molecules of NO 2 ?

6. Molar Mass- mass of 1 mol in g, Molar Mass- mass of 1 mol in g,  use periodic table & add up the masses,  round to 2 spaces past the decimal Types of molar mass: Types of molar mass:  Gram atomic mass- (gam) atomic mass of an element expressed in amu  Gram molecular mass- (gmm) molecular mass of a molecule expressed in g/mol  Gram formula mass- (gfm) formula mass of a salt expressed in g/mol

7. Find the molar mass & number of particles of the following: Find the molar mass & number of particles of the following: 1 mol C 1 mol C 1 mol CH 4 1 mol CH 4 1 mol (NH 4 ) 2 CO 3 1 mol (NH 4 ) 2 CO 3 1 mol CaCl 2 1 mol CaCl 2

8. Notes Be able to convert moles to mass: Be able to convert moles to mass:  Multiply by: Molar mass (g) 1 mol  How many g are in 9.45 mol N 2 O 3 ?

9.  Be able to convert mass to moles:  Multiply by: 1 mol Molar mass (g)  How many moles are in 92.2 g Fe 2 O 3 ?

10. Chalk Lab Question: How many grams, moles, ions and molecules are in your name? GPS ScSH 1-7, Sc2c Question: How many grams, moles, ions and molecules are in your name? GPS ScSH 1-7, Sc2c Procedure: Chalk is CaCO 3 Procedure: Chalk is CaCO 3  Get the mass of the chalk  Write your name on the designated surface  Get the mass of the chalk  Find the difference- this is the mass used to write your name  Convert the mass to moles  Convert the mass to molecules; write the number of molecules next to your name on the designated surface  Convert the mass to the number of atoms  Find the % of each element in chalk

11. For all substances: For all substances:  1 mol=molar mass=6.02 X 10 23 particles FOR GASES ONLY: FOR GASES ONLY:  1 mol=molar mass=6.02 X 10 23 particles  Molar volume- 1 mol of gas at STP has 22.4 L  ONLY at STP (standard temperature & pressure) OºC &101.3kpa or 1 atm 1mol= 22.4L

12. Convert mol  volume Convert mol  volume Multiply by: Multiply by:22.4L 1 mol Determine the volume of 0.60 mol SO 2 at STP. Determine the volume of 0.60 mol SO 2 at STP. To convert from volume  mol invert the conversion factor To convert from volume  mol invert the conversion factor Determine the number of moles in 2 L of CO 2 gas at STP. Determine the number of moles in 2 L of CO 2 gas at STP.

13. Can also use density to solve problems Can also use density to solve problems D=mass/volume= m/v=g/L D=mass/volume= m/v=g/L D of a gas containing C & O is 1.964 g/L at STP. Determine that molar mass. D of a gas containing C & O is 1.964 g/L at STP. Determine that molar mass. What is the density of krypton gas at STP? What is the density of krypton gas at STP?

14. Multi-step problems- convert to moles then to desired unit Multi-step problems- convert to moles then to desired unit Calculate the number of molecules in 60.0g NO 2. Calculate the number of molecules in 60.0g NO 2.

15. Lab Lab Title: The Mole Title: The Mole GPS Correlation: ScSH1-7, Sc2c GPS Correlation: ScSH1-7, Sc2c Purpose: To find the number of moles present in a given sample Purpose: To find the number of moles present in a given sample Materials: sample, balance, weigh boat Materials: sample, balance, weigh boat Procedure: Procedure:  1. Put weigh boat on balance & press re- zero  2. Add sample to weigh boat & record mass  3. Return sample to vial Observations: Observations:  Mass of sample _________  Name of sample ________

16. Conclusion Questions: Conclusion Questions:  Copy & Answer, Show ALL Work for Credit 1. How many moles did your sample contain? 1. How many moles did your sample contain? 2. How many grams would 1.00 mole of your sample contain? 2. How many grams would 1.00 mole of your sample contain? 3. How many particles would 1.00 mole of your sample contain? 3. How many particles would 1.00 mole of your sample contain? 4. How many grams would 2.00 moles of your sample contain? 4. How many grams would 2.00 moles of your sample contain? 5. How many particles would 2.00 moles of your sample contain? 5. How many particles would 2.00 moles of your sample contain? 6. How many atoms does your sample contain? 6. How many atoms does your sample contain? 7. On a scale of 1(awesome)-5(awful), how would you rate your performance on this lab? Explain. 7. On a scale of 1(awesome)-5(awful), how would you rate your performance on this lab? Explain. 8. Write a 2 sentence conclusion for this lab. 8. Write a 2 sentence conclusion for this lab.

17. Notes % Composition: relative amount of each element in compound or % by mass of each element in compound % Composition: relative amount of each element in compound or % by mass of each element in compound % mass= g desired element X 100 % mass= g desired element X 100 total g of compound  Make sure the % add up to 100. If 8.20 g Mg combines with 5.40g O, what is the % of each compound? Calculate the % composition of C 3 H 8 Calculate the % composition of C 3 H 8

18. Can use as conversion factor: Can use as conversion factor: Mass element in formula(molecule) Total mass of formula (molecule)  Calculate mass C in 82.0g C 3 H 8

19. Lab: Lab: Title: % Composition of Gum Title: % Composition of Gum Purpose: To find the % of sugar in gum Purpose: To find the % of sugar in gum Materials: Watch, gum, balance Materials: Watch, gum, balance Procedure: Procedure:  1. Get balance from cabinet  2. Mass gum IN WRAPPER  3. Take gum out of wrapper & chew for 15 minutes  4. While chewing gum, mass wrapper  5. After 15 min, put gum back in wrapper & get mass

20. Observations: Observations:  Mass of gum in wrapper _______  Mass of wrapper __________  Mass of gum after chewing _______ Calculations: Calculations: 1. Find true mass of gum by subtracting the mass of the wrapper from the chewed & unchewed gum ___________ 1. Find true mass of gum by subtracting the mass of the wrapper from the chewed & unchewed gum ___________ 2. Subtract unchewed mass from chewed mass (this is the mass of the sugar) 2. Subtract unchewed mass from chewed mass (this is the mass of the sugar) Find the % sugar in the gum Find the % sugar in the gum Conclusions: Write a sentence summing up your data Conclusions: Write a sentence summing up your data

21. Empirical Formula- lowest whole number ratio of elements in a compound Empirical Formula- lowest whole number ratio of elements in a compound Molecular formula- # of elements in a compound as it appears in nature Molecular formula- # of elements in a compound as it appears in nature  May or may not be the same as empirical HO is empirical formula HO is empirical formula H 2 O 2 is molecular H 2 O 2 is molecular CO 2 empirical & molecular are the same CO 2 empirical & molecular are the same

22. To find empirical formula: To find empirical formula:  1. Change % to g  2. Change g to mol  3. Find ratio of moles  4. Ratios become subscripts in formula  Tricks- if molar ratio is: –.5 X by 2 –.3 or.6 X 3 –.25 or.75 X 4 –.2 or lower, round down –.8 or above round up

23. Determine the empirical formula of a compound that contains35.98%Al & 64.02%S. Determine the empirical formula of a compound that contains35.98%Al & 64.02%S.

24. What is the empirical formula of a compound that is 25.9 % N & 74.1%O? What is the empirical formula of a compound that is 25.9 % N & 74.1%O?

25. What is the empirical formula of a compound that contains 10.89%Mg, 31.77%Cl & 57.34%O? What is the empirical formula of a compound that contains 10.89%Mg, 31.77%Cl & 57.34%O?

26. If they give you molecular mass: If they give you molecular mass:  1. Get mass of empirical formula (what you just found)  2. Divide molecular mass/empirical  3. Multiply that # by subscripts

27. Calculate molecular formula of compound whose molar mass is 60.0g & the empirical formula is CH 4 N. Calculate molecular formula of compound whose molar mass is 60.0g & the empirical formula is CH 4 N.

28. A compound is composed of 40.68% C, 5.08% H & 54.24%O. It has a molecular mass of 118.1g/mol. Find the empirical & molecular formula. A compound is composed of 40.68% C, 5.08% H & 54.24%O. It has a molecular mass of 118.1g/mol. Find the empirical & molecular formula.