Transcript
Launch: 11/24 Grab you binder and immediately take a seat!
1. What is a mole?
2. What is Avogadro’s number?
3. How is a mole defined? (Hint: use the word carbon)
Launch 11/24 5. How many moles are there in 6g of carbon-12?
a. .5 moles b. 1 mole
c. 2 moles d. 12 moles
Announcements This is a really important week!
Points end tomorrow Block 5 is in the lead Be engaged Be respectful
What is molar mass? Mr. Heffner 11/24/09
What is a molar mass? Molar mass is…
the sum of all of the atomic masses in a molecule
5
B Boron 10.81 Atomic
mass
What is a molar mass? Molar mass is…
the sum of the atomic masses in a molecule
H2O Molar mass = mass of H + mass of H + mass of O = 1.01 + 1.01 + 16.00
= 18.02 g/mol Units!
What is a molar mass? Molar mass is…
the sum of the atomic masses in a molecule
NH3 Molar mass = mass of N + mass of H + mass of H + mass of H
= mass of N + 3X(mass of H)
= 14.01 + 3X(1.01) = 14.01 + 3.03
= 17.04 g/mol Units!
What is a molar mass? Molar mass is…
the sum of the atomic masses in a molecule
C2H2 Molar mass = mass of C + mass of C + mass of H + mass of H
= 2X(mass of C) + 2X(mass of H)
= 2X(12.01) + 2X(1.01) = 24.02 + 2.02
= 26.04 g/mol Units!
What is a molar mass? Molar mass is…
the sum of all of the atomic masses in a molecule a.k.a molecular mass or molecular weight
basically, how much 1 mole of a molecule weighs
Whiteboards Work in pairs
Trade-off marker every question
You have 60 seconds to draw the answer Show all of your work! Don’t forget units!
Lift board only when prompted
What is the molar mass of of fluorine (F)?
What is the molecular mass of O2?
What is the molecular mass of CH4?
What is the molecular weight of SOCl2?
What is the molar mass of Ca(OH)2?
What is the molecular weight of CH2COOH?
Practice Questions Practice question worksheet
Exit Slip 1. Molar mass is
a. a number with the units g/meters b. the number of molecules in a gram of a substance
c. the sum of all of the atomic masses in a molecule d. calculated by adding up the atomic numbers in a
molecule
Exit Slip 2. Molar mass is also called
a. molecular mass b. molecular weight
c. molar weight d. both a & b
Exit Slip 3. What is the molar mass of oxygen (O)?
a. 1.00 g/mol b. 8.00 g/mol
c. 16.00 g/mol d. 32.00 g/mol
Exit Slip 4. Which of the following show the correct way to
calculate the molecular weight of CH3OH? a. 12.01 + 3 X (1.01) + 16.00 b. 12.01 + 4 X (1.01) + 16.00 c. 12.01 + 1.01 + 16.00
d. 6.00 + 1.00 + 8.00
Exit Slip 5. What is the molecular mass of Mg(OH)2
a. 24.31 g/mol b. 41.32 g/mol
c. 58.33 g/mol d. 100 g/mol
Homework Finish practice questions
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