Upload
malachi-noel
View
217
Download
0
Tags:
Embed Size (px)
Citation preview
Objectives: Moles are a Chemist Best Friend• I can identify what a mole is in chemistry.
• I can convert between moles and representative particles of substances.
• I can convert between moles and mass of substances.
• I can calculate the percentage composition of substances.
Grouping Matter• Easy way to measure all matter. r500
Dozen dougnuts= 12
Gross of pencils= 144
Ream of paper = 500 Byte of information storage= 4 bits
Grouping Matter• How do scientists’ group the representative
particles that make-up matter?
Representative particles: substances that make-up matter.
Examples: • Atoms• Ionic Compounds• Molecules (covalent cmpds.)
nclark.net
Grouping Representative Particles
1 mole = 6.02x1023 representative particles (Avogadro’s Number)
• “The Mole is a Unit Song” (nclark.net)
A mole is used to group representative particles.
Mole Map
number ofrepresentative
particles
mass
1 mol22.4L
22.4L1 mol
6.02 x 10 particles1 mol
23
6.02 x 10 particles231 mol
1 molmolar mass
molar mass1 mol
moles
volumeat STP
Converting Moles to Representative ParticlesEx. Propane (C3H8) is a gas used for cooking and
heating. How many molecules of propane is equal to 2.4 moles of propane?
Convesion: Representative Particles to Moles Ex. Magnesium is a light metal used in the
manufacture of aircraft and automobile wheels. How many moles of magnesium equals 1.25x1023
atoms of magnesium?
Mole Map
number ofrepresentative
particles
mass
1 mol22.4L
22.4L1 mol
6.02 x 10 particles1 mol
23
6.02 x 10 particles231 mol
1 molmolar mass
molar mass1 mol
moles
volumeat STP
Bell Ringer: Moles1. Define and give two examples of a representative
particle.2. a. What is a mole? b. How many atoms are in a mole of Cu?
3. How many moles are in 4.65x1024 molecules of CO2 ?
Conversions: Mole-Representative Particles
(Homework Problems Key)
1. 1.2x1024 molecules (2sig. Figs)2. 9.0x1023 molecules (2 sig figs)3. 4.5x1023 molecules (2 sig figs)4. 9.0x1024 molecules (2 sig figs)5. 2.1x1023 molecules (2 sig figs)1. 1.00 moles (3 sig figs)2. 2.00 moles (3 sig figs)3. 2.5x10-4 moles (2 sig figs)4. 5.6x102 moles (2 sig figs)5. 1.2x10-4 moles (2 sig figs)
Objectives: Moles are a Chemist Best Friend• I can identify what a mole is in chemistry.
• I can convert between moles and representative particles of substances.
• I can convert between moles and mass of substances.
• I can calculate the percentage composition of substances.
Mole Map
number ofrepresentative
particles
mass
1 mol22.4L
22.4L1 mol
6.02 x 10 particles1 mol
23
6.02 x 10 particles231 mol
1 molmolar mass
molar mass1 mol
moles
volumeat STP
Converting Moles to Mass• How do we convert from the moles of a
substance to the mass of a substance?
Conversion: Moles- Mass• Mole-Mass Conversion: 1 mole of a substance = molar mass of the substance
• Molar mass = substance’s atomic mass in grams
Molar Mass of an Element• Molar mass = element’s atomic mass(grams)• Round atomic mass to tenths place.
Ex. A mole of sulfur has a molar mass of?
Ex. A mole of sodium has a molar mass of?
Molar Mass of a Compound• Molar mass = sum of the elements’ atomic masses
in the compound • Need chemical formula to calculate the molar
mass of a compound.Ex. A mole of NaCl has a molar mass of?
Ex. A mole of H2O has a molar mass of?
Bell Ringer: Chemistry1. What is the representative particle for each substance
below? (atom, ionic compound, or molecule)
a. Na2O b. Fe c. H2 d. Ne
2. How many atoms are in 2.5 moles of copper?
3. a. What is the molar mass of silver, Ag?
b. What is the molar mass of Al2(CO3)3?
Mole-Mass Conversions• 1 mole = molar mass of substanceEx. When iron is exposed to air, it corrodes to form
red-brown rust. How many moles of iron (III) oxide are contained in 92.2g of pure Fe2O3?
Mole Map
number ofrepresentative
particles
mass
1 mol22.4L
22.4L1 mol
6.02 x 10 particles1 mol
23
6.02 x 10 particles231 mol
1 molmolar mass
molar mass1 mol
moles
volumeat STP
Mole-Mass ConversionsEx. What is the mass of 9.45 moles of aluminum
oxide? (1 mole = molar mass of a substance)
Mole Map
number ofrepresentative
particles
mass
1 mol22.4L
22.4L1 mol
6.02 x 10 particles1 mol
23
6.02 x 10 particles231 mol
1 molmolar mass
molar mass1 mol
moles
volumeat STP
Mole Conversions
Mole to Particle Conversion:1 mole = 6.02x1023 particles (atoms or cmpds)
Mole to Mass Conversion:1 mole = molar mass of the substance (grams)
Mole Map
number ofrepresentative
particles
mass
1 mol22.4L
22.4L1 mol
6.02 x 10 particles1 mol
23
6.02 x 10 particles231 mol
1 molmolar mass
molar mass1 mol
moles
volumeat STP
Bubble Gum Lab
• Purpose: Practice mole conversions and calculate the % composition of sugar in bubble gum.
Mole Map
number ofrepresentative
particles
mass
1 mol22.4L
22.4L1 mol
6.02 x 10 particles1 mol
23
6.02 x 10 particles231 mol
1 molmolar mass
molar mass1 mol
moles
volumeat STP
Chemical Quantities Objectives (Chpt.10)• I can identify what a mole is in chemistry.
• I can convert between moles and representative particles of substances.
• I can convert between moles and mass of substances.
• I can calculate the percentage composition of substances.
Bell Ringer: Mole Conversions1. Define “mole”. 2. Name the representative particle of each
substance. (atom, molecule, ionic compound)a. oxygen gas b. sodium sulfidec. potassium d. sulfur dioxide3. What is the molar mass of a substance?4. What is the conversion needed for each problem below?a. mole to representative particle conversion?b. mole to mass conversion?
Fun with Moles Review
Purpose: Work together in groups to competitively review mole conversion calculations learned before spring break.
Moles Conversion Review Worksheet1. 0.407 moles2. 1.8x1024 atoms3. a. 40.3g b. 74g c. 78g d.96 g4. 0.0417 mole AgCl5. 0.35 mole Cu(OH)2
6. 0.258 mol SiO2
7. 51 gH2O2
8. 120 g9. 1,040 g C5H12
10. 52.7 g Cu
Mole Map
number ofrepresentative
particles
mass
1 mol22.4L
22.4L1 mol
6.02 x 10 particles1 mol
23
6.02 x 10 particles231 mol
1 molmolar mass
molar mass1 mol
moles
volumeat STP
Mole Conversions: 2 step problems1. How many molecules are there in 100 grams of CCl4 ?
2. How many grams do 1.2x1021 molecules of BCl3 weigh?
Mole Conversion LabProblem: How many molecules are present in a
tablespoon of the following substances?a. sodium chlorideb.waterc. calcium carbonate
Design and conduct an experiment that will help you solve this problem. Make sure to include a hypothesis, data section, and conclusion.
Mole Map
number ofrepresentative
particles
mass
1 mol22.4L
22.4L1 mol
6.02 x 10 particles1 mol
23
6.02 x 10 particles231 mol
1 molmolar mass
molar mass1 mol
moles
volumeat STP
Percentage Composition of a Compound
• Percent of mass each element contributes to the compound’s molar mass.
• How do we calculate % composition of a compound?
% Composition from Chemical Formula
% mass of element =
Ex. Propane, C3H8 is one of the compounds obtained from petroleum and is used to fuel homes and gas grills. Calculate the percent composition of propane.
% Composition of Compound• What is the % composition of each element in
the following compound, Al(NO2)3 ?
% Composition as a Conversion Factor• Use % composition data to calculate the mass of an
element in a specific sample of that compound.
• Ex. What is the mass of Al in 6.5 g of Al(NO2)3 ?
% Composition as a Conversion Factor
• What is the mass of N in 6.5 g of Al(NO2)3 ?
• What is the mass of O in 6.5 g of Al(NO2)3?
Bell Ringer: Chemical Quantities1. How many grams are in 5.0 moles of Cs3N ?
2.How many moles are in 3.7x1021 cmpds. of NaCl?
3. What is the % composition of Cu2(SO4)?
4. How many grams of Cu are in 9.8 g of Cu2(SO4)?