Download 7.1: “Avogadro`s Number and Molar Conversions” Day 1 Atoms

7.1: “Avogadro’s Number and Molar Conversions” Day 1
1. Atoms, _________, and molecules are very __________, so even tiny samples have huge
numbers of _________________.
a. Scientists use the __________ to make counting such large numbers
_________________.
b. Mole: the _________ unit for ___________; the number of __________ in
exactly 12 grams of carbon-12.
2. The ______________ is used to count out a given number of particles, whether they
are ___________, molecules, formula units, ___________, or electrons.
3. The number of particles in a ________ is called _________________ number.
a. Avogadro’s number is _________________________; the number of
__________ or molecules in 1.000 ___________.
4. Conversion Factors are Equivalent to _________.
a. 6.022 X 1023 particles = ____________________________
b. From this definition, we get 2 conversion factors:
5. Because a ________________ factor is equal to ________, it can multiply any
quantity without changing the __________.
a. Only the ________ are changed.
b. When solving problems, the _________ that you know goes on the
_____________ of the fraction. (You’re kicking it out so it needs to be close to
your foot at the bottom of the fraction…)
6. You can use Conversion Factors to ______________ from one Unit to Another
(Dimensional Analysis)
Example #1: How many eggs are there in 5 dozen?
Example #2: If you have 548 plain white socks, how many pairs can you make?
7. Changing Moles
Particles; Sample Problem A, pg. 228
Find the number of molecules in 2.5 mol of sulfur dioxide, SO2.
1.
Start with what you know: 2.5 mol SO2
2. Multiply by conversion factor to change moles
2.5 mol SO2 X
6.022 X 1023 molecules SO2
particles:
= 1.5 X 1024 molecules SO2
1 mol SO2
8. Changing Moles
Particles; Practice #1
How many particles are there in 2.45 X 10
1.
(2 sig figs)
-6
mol of nickel (II) selenide, NiSe?
Start with what you know:
2. Multiply by conversion factor to change moles
9. Changing Moles
particles:
Particles; Practice #2
How many atoms are there in 4.3 moles of tungsten, W?
1. Start with what you know:
2. Multiply by conversion factor to change moles
atoms:
10. We can go the other way too and change ____________
11. Changing Particles
____________
Moles; Sample Problem B, pg. 229
A sample contains 3.01 X 1023 molecules of sulfur dioxide, SO2. Determine the amount in
moles.
1.
Start with what you know: 3.01 X 1023 molecules SO2
2. Multiply by conversion factor to change atoms
3.01 X 1023 molecules SO2
X
1 mol SO2
moles:
= 0.500 mole SO2
6.022 X 1023 molecules SO2
12. Changing Particles
(3 sig figs)
Moles; Practice #1
How many atoms are equivalent to 6.93 X 1023 thallium atoms, Tl?
1.
Start with what you know:
2. Multiply by conversion factor to change atoms
13. Changing Particles
moles:
Moles; Practice #2
How many moles are equivalent to 7.95 X 1024 copper (II) chloride, CuCl2, formula units?
1.
Start with what you know:
2. Multiply by conversion factor to change formula units
moles: