Drill: Calculate the % composition of each element in
H4N2O3
Return Tests & Review Drill
& Test
4 H = 4.0 sum2 N = 28.0 = 80.03 O = 48.0
% H = 4.0/80.0 x 100 % = 5.0% H
% N = 28.0/80.0 x 100 % = 35.0 % N
% O = 48.0/80.0 x 100 % = 60.0 % O
Name each of the following:
•CuO MnS
•SeO2 Na2O
•SnCl2 MnF2
•HClO3 CCl4
Anyone who missed or failed the test may retake a similar test
within a week to bring the grade up to 60.
CHM II HW•Review PP 06•Work the problems attached to Poly’s website.
Are there any questions on
previous material?
Moles•The standard unit of measure for the
amount of a substance
Dozen= 12 of anything
Moles= 6.022 x 1023
of anything
Moles= the amount of a
substance that would = its mass in g from the PT
Describe the factor label method of
conversions
Molar Conversions• Mass to moles
• Volume of a gas to moles
• Particles to moles
• Volume of a solution to moles
moles
mass
volumeof a gas
Atoms ormolecules
solution volume
Mass to Moles•Use atomic masses from the periodic table
•NaCl = 58.5 g/mole
Gas Volume to Moles•At STP: 22.4 L/mole
•Non-STP: PV = nRTPV
RTn =
Particles to Moles•Use Avogadro’s Number
•6.02 x 1023 atoms, molecules, etc/mole
Soln Volume to Moles
•Multiply molarity times volume
•n = M x V
Solution Measures•Molarity (M) = the number of moles of solute per liter of solution. Others later
•Convert 7.0 g of silicon to
moles
Convert 250 g of CaCO3
to moles
Convert 3.0 moles of helium
to grams
Convert 11.2 L of oxygen gas
at STP to moles
Convert 0.20 moles of helium to
volume at STP
Convert: 2.0 x 1024 atoms
He to moles
Drill: Convert 3.0 moles of glucose to molecules
Review & Collect Drill
& HW
CHM II HW• Review PP-6
• Work the attached problem & turn it in on Monday
• We will have a lab on Friday.
Are there any questions on
previous material?
Convert 250 mL of 0.10 M HCl
to moles
Convert6.8 g NH3 to
volume of gas at STP
Drill: Determine the volume
required to make 60.0 g NaOH into a 0.75 M solution
Review & Collect Drill
& HW
CHM II HW•Review PP-6
•Complete the attached assignment & turn it in tomorrow.
Are there any questions on
previous material?
Convert3.0 x 1025
molecules of CO2 to mass in kg
Drill: Calculate the number
molecules in 32 g of Fe2O3
Calculate the number of atoms
in 16 ng of Fe2(SO4)3
•Lowest whole number ratio of elements in a compound
•C6H12O6: EF = CH2O
Determining Empirical
formulas from percent
composition
• Assume 100 g• Change % directly to grams• Use molar conversions to
convert grams to moles• Divide each molar amount
by the smallest molar amount
Find empirical for a compound with:
70.0 % Fe30.0 % O
Find empirical for a compound with:
40 % Ca12 % C48 % O
Find empirical for a compound with:
40.0 % C6.7 % H
53.3 % O
•The actual whole number for each element in the
compound
Molecular FormulaC6H12O6
Empirical FormulaCH2O
Solving MF from EF1) Solve empirical mass
2) Divide EM into MM
3) Multiply EF by quotient
Drill: Calculate the mass of solute required to make
40.0 mL of0.25 M Pb(NO3)2
Test Review on Nomenclature,
Molar conversions, & %
Composition.
Calculate the % composition of each element in
Pb(NO3)2
Calculate the empirical formula of a substance containing
62.7 % Po, 28.8 % O, & 8.4 % N.
Calculate the molecular formula of a substance with an empirical formula of NH2 & a molecular mass of 32 g/mole.
Name each of the following:
•SeO MgS
•PbO2 Cl2O
•KNO3 ScCl3
Derive formulas for each:
•Cesium oxide
•Barium chloride
•Calcium phosphate
•Manganese(II) chlorate
Name each of the following:
NH4Cl BaSO4
KC2H3O2 K2HPO3
KNO3 CuBrO
Li2CO3 MgC2O4
Name each of the following:
HCl H2SO4
H2S H3PO3
HNO3 HBrO
H2CO3 HBrO4
Calculate the number of
hydrogen atoms in 1.8 kg of PH5.
Calculate the volume at STP of
6.0 ng of NO.
Calculate the mass of KBr required to make 250 mL of a 0.40 M solution.