September 19, 2012 Ms. Boon Chemistry

 Pick up your assignment report.
 Make a list of at least 3 things you are proud of concerning your academic achievements this year.
 Make a list of at least 3 things you would like to improve about your school work.

 The following students demonstrated mastery (3 or
4) of all the Unit 2 standards on their Unit 2 exam:
 Edgardo Aguilar & Denise Montes
 The following students have demonstrated mastery of all Unit 2 standards on average:
 Christian Romo, Zamir Ramirez, Rumaldo Godinez, and Susan Castellanos

 The following students demonstrated mastery (3 or
4) of all the Unit 2 standards on their Unit 2 exam:
 Eduardo Cabral, Irma Castillo, Christopher
Orellana, & Diana Portillo
 The following students have demonstrated mastery of all Unit 2 standards on average:
 Douglas Garcia, Gerardo Garcia, Christopher
Orellana, Diana Portillo, and Andres Valencia

 The following students demonstrated mastery (3 or
4) of all the Unit 2 standards on their Unit 2 exam:
 Karla Giron, Kiemon Gordon & Abel Martinez
 The following students have demonstrated mastery of all Unit 2 standards on average:
 Patrick Jones, Antonio Ojeda, Luis Orellana, and
Briceida Pacheco

 The following students demonstrated mastery (3 or
4) of all the Unit 2 standards on their Unit 2 exam:
 Luis Ayala, Jonathan Mendez, Alberto Payan,
Surmani Sanford, Angel Tapia & Xochilt Villafana
 The following students have demonstrated mastery of all Unit 2 standards on average:
 Angel Tapia

 The following students demonstrated mastery (3 or
4) of all the Unit 2 standards on their Unit 2 exam:
 Melissa Alvarez, Kevin Chavez & Sabrina
Montgomery
 The following students have demonstrated mastery of all Unit 2 standards on average:
 Melissa Alvarez, Kevin Chavez, Deya Garcia, Sabrina
Montgomery, & Christine Romo

 I can use my periodic table to calculate the molar mass of any element, compound, or molecule.

 Catalyst & Shout Outs
 Homework Review
 Molar Mass Puzzle Activity
 Exit Slip

HW Review: Read pp. 230-233; problems: pp. 233 #11, pp. 240 #5 & 10(a, b, c, & e)
 (233) 11. The mass of 6.022 x 10 23 molecules of ibuprofen is 206.31 g.
 (To solve, we must remember that 6.022 x 10 23 molecules = 1 mole and that the mass of 1 mole of a molecule is whatever that molecule’s molar mass is.
The question gave us the molar mass as 206.31 g/mol.)

HW Review: Read pp. 230-233; problems: pp. 233 #11, pp. 240 #5 & 10(a, b, c, & e)
 5. What is the ratio of N and H atoms in NH
3
?
 1N:3H For every N atom there are 3 H atoms.

HW Review: Read pp. 230-233; problems: pp. 233 #11, pp. 240 #5 & 10(a, b, c, & e)
 10(a). Molar mass of CsCl -- Answer: 168.35 g/mol
 Steps to Solve: (1) Find the molar mass of the individual elements. Use the periodic table. The molar mass is the same as the average atomic mass. Just change the units from amu to g/mol.
 Cs = 132.905 g/mol Cl = 35.453 g/mol
 (2) Use the compound formula to determine how many of each element is in the compound.
 CsCl is a 1:1 ratio of Cs and Cl (there are no subscript numbers telling us differently)
 (3) Add the molar masses in the correct ratio.
 1 mol Cs = 132.90 g
 1 mol Cl = 35.453 g
 132.90g + 35.453 g = 168.353 g/mol (rounded = 168.35 g/mol)

 (b) Molar mass of KClO
3
? Answer: 122.55 g/mol
 Steps to Solve: (1) Find the molar mass of the individual elements. Use the periodic table. The molar mass is the same as the average atomic mass. Just change the units from amu to g/mol.
 K = 39.098 g/mol Cl = 35.453 g/mol O = 15.999 g/mol
 (2) Use the compound formula to determine how many of each element is in the compound.
 KClO
3
1K: 1Cl: 3O
 (3) Add the molar masses in the correct ratio.
 1 mol K = 39.098 g
 1 mol Cl = 35.453 g
 3 mol O = 15.999 g x 3 = 47.997 g
 39.098 g + 35.453 g + 47.997 g = 122.55 g/mol
 (c) Molar mass of C
6
H
12
O
6
? Answer: 180.18 g/mol
 (e) Molar mass of C
2
H
5
NO
2
? Answer: 75.08 g/mol

 Instructions:
 Work with a partner
 You will receive a stack of puzzle pieces.
 Half have an element or compound formula and the other half have the molar mass.
 Match the formula with the molar mass.
 Write the answers down.
 When you think you have all the answers, raise your hand and Ms. Boon will check.

1. What is the molar mass of Potassium?
2. What is the molar mass Potassium Chloride (KCl)?
3. What is the molar mass of ozone (O
3
)?
4. The molar mass of NaCl is 58.44 g/mol. What is the mass of 2 moles of NaCl?
5. One mole of water contains 6.02 x 10 23 molecules.
How many water molecules are in 3 moles of water?