# Moles are a Chemist Best Friend Chapter 10 nclark.net.

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Moles are a Chemist Best Friend Chapter 10 nclark.net

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.

Measuring Matter What are three ways we can measure matter? 1. 2. 3. hermitwoods.com

Measuring Apples stockphotos.it rainycity.com flickr.com

Grouping Matter Easy way to measure all matter. r500 Dozen dougnuts= 12 Gross of pencils= 144 Ream of paper = 500Byte 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

Classification of Matter

Grouping Representative Particles 1 mole = 6.02x10 23 representative particles (Avogadro’s Number) “The Mole is a Unit Song” (nclark.net) A mole is used to group representative particles.

Mole Map

Converting Moles to Representative Particles Ex. Propane (C 3 H 8 ) 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 1.25x10 23 atoms of magnesium?

Mole Map

Bell Ringer: Moles 1.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 4.65x10 24 molecules of CO 2 ?

Conversions: Mole-Representative Particles ( Homework Problems Key) 1.1.2x10 24 molecules (2sig. Figs) 2.9.0x10 23 molecules (2 sig figs) 3.4.5x10 23 molecules (2 sig figs) 4.9.0x10 24 molecules (2 sig figs) 5.2.1x10 23 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) 4.5.6x10 2 moles (2 sig figs) 5.1.2x10 -4 moles (2 sig figs)

Conversion: Mole-Representative Particles Homework Problems

Converting Moles to Mass How do we convert from moles to mass?

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-Mass Conversion

Mole Map

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 H 2 O has a molar mass of?

Bell Ringer: Chemistry 1.What is the representative particle for each substance below? (atom, ionic compound, or molecule) a. Na 2 O b. Fe c. H 2 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 Al 2 (CO 3 ) 3 ?

Mole Packet Questions

Mole-Mass Conversions 1 mole = molar mass of substance Ex. 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 Fe 2 O 3 ?

Mole Map

Mole-Mass Conversions Ex. What is the mass of 9.45 moles of aluminum oxide? (1 mole = molar mass of a substance)

Mole Map

Mole Conversions Mole to Particle Conversion: 1 mole = 6.02x10 23 particles (atoms or cmpds) Mole to Mass Conversion: 1 mole = molar mass of the substance (grams)

Mole Map

Bubble Gum Lab Purpose: Practice mole conversions and calculate the % composition of sugar in bubble gum.

Mole Map

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 Conversions 1.Define “mole”. 2.Name the representative particle of each substance. (atom, molecule, ionic compound) a.oxygen gas b. sodium sulfide c.potassium d. sulfur dioxide 3.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?

Chemical Quantities Quiz Questions

Fun with Moles Review Purpose: Work together in groups to competitively review mole conversion calculations learned before spring break.

Moles Conversion Review Worksheet 1.0.407 moles 2.1.8x10 24 atoms 3. a. 40.3g b. 74g c. 78g d.96 g 4.0.0417 mole AgCl 5.0.35 mole Cu(OH) 2 6.0.258 mol SiO 2 7.51 gH 2 O 2 8.120 g 9.1,040 g C 5 H 12 10. 52.7 g Cu

Mole Map

Mole Conversions: 2 step problems 1.How many molecules are there in 100 grams of CCl 4 ? 2. How many grams do 1.2x10 21 molecules of BCl 3 weigh?

Mole Conversions: 2 step Problems

Mole Conversion Lab Problem: How many molecules are present in a tablespoon of the following substances? a.sodium chloride b.water c.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 Conversion Lab Questions

Mole Map

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, C 3 H 8 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(NO 2 ) 3 ?

Mole Conversions: 2 step Problems

% 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(NO 2 ) 3 ?

% Composition as a Conversion Factor What is the mass of Al in 6.5 g of Al(NO 2 ) 3 ?

% Composition as a Conversion Factor What is the mass of N in 6.5 g of Al(NO 2 ) 3 ? What is the mass of O in 6.5 g of Al(NO 2 ) 3 ?

Bell Ringer: Chemical Quantities 1.How many grams are in 5.0 moles of Cs 3 N ? 2.How many moles are in 3.7x10 21 cmpds. of NaCl? 3.What is the % composition of Cu 2 (SO 4 )? 4. How many grams of Cu are in 9.8 g of Cu 2 (SO 4 )?

Hydrate Lab Hydrate: Cu(SO 4 ). H 2 O Anhydrous salt: Cu(SO 4 )

Mole Map