chapter 10: the mole 1 mole = 6.02 x 10 23 particles a mole is also called avogadros number
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Chapter 10: The Mole
1 mole = 6.02 x 1023 particlesA mole is also called Avogadro’s number.
A paper clip is 3.2 cm in length. How many times can of mole of paper clips go around the Earth? (Circumference of the Earth is 25,000 miles, 1 in = 2.54 cm, 1 foot = 12 inches,1 mile = 5,280 feet)
6.02 x 10 23 particles – atoms, molecules, formula units
P. 287-290
Conversions: Moles Particles, Particles Moles P.290-291
# of moles x 6.02 x 10 23 particles = particles mole
# particles x mole = moles 6.02 x 10 23 particles
Freon - CCl2F2 study sample problem 10.3 on p. 292
How many Fluorine atoms are in 5.5 moles of Freon?
5.5 mol of CCl2F2 x 2 mol F Atoms = 11 mol of F atoms
1 mol of CCl2F2
The Mass of a Mole of an Element P. 293-294
Conversions: moles mass, mass moles
# of moles x # of grams = grams mole
grams x mole = moles# of grams
The Mass of a Mole of a Compound P. 295-296
What is the molar mass of Potassium Chromate?
The Mole to Mass Relationship P.297-298
1. Find the molar mass of the compound.
2. Convert moles to grams by using molar mass as a conversion factor.
Converting Moles to Mass - P. 298-299
Converting Mass to Moles of a Compound – P. 299
Particles Mass, Mass Particles
Move through the mole tunnel.
Mole (tunnel)
mass
Units (atoms, molecules)
6.02 x 1023
Molar Mass
Converting Mass to Particles
Calculating Percentage Composition P.305-307
% composition of an element = mass of element x 100% mass of compound
1. A compound is formed when 9.03 g of Mg combines with 3.48 g of N. What is the percent composition of the compound?
2. When a 14.2 g sample of mercury(II)oxide is decomposed into its elements by heating, 13.2 g of mercury is obtained. What is the percent composition of the compound?
3. Calculate the percentage composition of dicarbon hexahydride, sodium hydrogen sulfate and phosphoric acid.
Empirical Formula – The Simplest Formula P.309-310
• Convert % grams (Assume 100 g)• Convert grams moles• Divide each mole quantity by the smallest mole quantity• Can’t have decimals
• Convert grams moles
• Divide each mole quantity by the smallest mole quantity.
Determining Molecular FormulaA True Formula P.311-312
1.Determine the empirical formula.
2.Divide the molar mass by the molar mass of the empirical formula.
Hydrates
Opal – Silicon Dioxide an example of a hydrateWater is bonded to the atoms of the compound.
Desiccators
Removes water from the
surroundings.
Circuitry. Electronics and
optics.
Calcium Sulfate
Not soluble in alcoholCalcium Chloride
Naming Hydrates
• State the name of the substance and then add a prefix in front of the word hydrate
Ex. Na2CO3 * 10H2O – sodium carbonate decahydrate
Hydrated CoCl2
11.75 g before heating
Anhydrous CoCl2
w/o water
9.25 g after heating
Analyzing Hydrates
Analyzing Hydrates
• Find the mass of the water.• Determine the moles of the compound and
water. • Divide by the smallest mole ratio.
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