1 Chemical Quantities or. 2 Representative particles n The smallest pieces of a substance. n For an element it is an atom. (Ex: Na) n For a covalent compound.

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Chemical QuantitiesChemical Quantitiesoror

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Representative particlesRepresentative particles The smallest pieces of a substance.The smallest pieces of a substance. For an For an elementelement it is an it is an atomatom. (Ex: Na). (Ex: Na) For a For a covalent compound covalent compound it is a it is a

moleculemolecule. (Ex: CO. (Ex: CO2 2 , H, H22)) For an For an ionic compound ionic compound it is a it is a

formula unitformula unit. (Ex: NaCl). (Ex: NaCl)

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Mole Video

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What is a Mole?What is a Mole? A unit of counting atoms and A unit of counting atoms and

molecules. molecules. 1 mole is 6.02 x 101 mole is 6.02 x 102323 particles. particles. 6.02 x 106.02 x 102323 is called is called Avogadro'sAvogadro's

number.number.

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What is a Mole?What is a Mole? A mole is like a dozen. A dozen is A mole is like a dozen. A dozen is

defined as 12.defined as 12. A dozen eggs = 12 eggs, a dozen A dozen eggs = 12 eggs, a dozen

pencils = 12 pencils, etc…pencils = 12 pencils, etc… A mole is defined as 6.02 x 10A mole is defined as 6.02 x 102323. . A mole of pencils = 6.02 x 10A mole of pencils = 6.02 x 102323

pencilspencils A mole of baseballs = 6.02 x 10A mole of baseballs = 6.02 x 102323

baseballsbaseballs

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What is a Mole?What is a Mole? Avogadro’s number is a very large Avogadro’s number is a very large

number!number! 602,000,000,000,000,000,000,000602,000,000,000,000,000,000,000 If there were a mole of rice grains, all If there were a mole of rice grains, all

the land area in the whole world the land area in the whole world would be covered with rice to a would be covered with rice to a depth of 75 meters!depth of 75 meters!

A mole of hockey pucks would be A mole of hockey pucks would be equal to the mass of the moon.equal to the mass of the moon.

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A Mole is A Lot of ThingsA Mole is A Lot of Things Assuming that each human being Assuming that each human being

has has 60 trillion body cells 60 trillion body cells (6.0 x 10(6.0 x 101313) ) and the Earth’s population is and the Earth’s population is 7.057.05 billionbillion, the total number of living , the total number of living human body cells on the Earth at the human body cells on the Earth at the present time is present time is 4.2 x 104.2 x 102323 or about or about 2/3 2/3 of a mole!of a mole!

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A Mole is A Lot of ThingsA Mole is A Lot of Things If If one mole one mole of pennies were divided of pennies were divided

up among the Earth’s population, up among the Earth’s population, each person would receive each person would receive 8.54x108.54x101313 penniespennies. Personal spending at the . Personal spending at the rate of rate of one million dollars a day one million dollars a day would use up each persons wealth in would use up each persons wealth in just over just over 2300 years!2300 years! Life would not Life would not be comfortable. The surface of the be comfortable. The surface of the Earth would be covered in copper Earth would be covered in copper coins to a depth of at least coins to a depth of at least 420420 meters! meters!

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MassMass 1 atom 1 atom of sulfur = of sulfur = 3232 amuamu amu = atomic mass unitamu = atomic mass unit We do not measure mass in amu, we We do not measure mass in amu, we

use grams.use grams. 1 mole 1 mole of sulfur atoms = of sulfur atoms = 3232 gramsgrams 1 mole 1 mole of sulfur atoms = of sulfur atoms = 6.02 x106.02 x102323

atomsatoms

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MassMass

1 atom of Li =1 atom of Li = 1 mole of Li atoms =1 mole of Li atoms = 1 mole of Li atoms =1 mole of Li atoms =

1 molecule of H1 molecule of H22O = O =

1 mole of H1 mole of H22O O

molecules = molecules = 1 mole of H1 mole of H22O O

molecules =molecules =

7 amu7 amu

7 grams7 grams

6.02 x 106.02 x 102323 atoms atoms

18 amu18 amu

18 grams18 grams

6.02 x 106.02 x 102323 molecules molecules

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Molar MassMolar Mass The mass of 1 mole of a substance The mass of 1 mole of a substance

(in grams).(in grams). What is the molar mass of:What is the molar mass of:

1. Sn1. Sn

119 grams119 grams

2. Ba2. Ba

137 grams137 grams

3. Oxygen3. Oxygen

32 g (O32 g (O22))

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Molar MassMolar Mass4. C4. C1212HH2222OO1111

342 g342 g

5. Fe5. Fe22(SO(SO44))33

400 g400 g

6. Ca(C6. Ca(C22HH33OO22))22

158 g158 g

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Mole CalculationsMole Calculations

Mole – MassMole – Mass

1.1. What is the mass of 2.50 mol of What is the mass of 2.50 mol of potassium?potassium?

2.2. Convert 0.522 moles of Zn to grams.Convert 0.522 moles of Zn to grams.

3.3. 145 grams of silver = _____ moles145 grams of silver = _____ moles

4.4. 28.0 g of CO28.0 g of CO22 = _____ moles = _____ moles

5.5. 1.50 moles C1.50 moles C66HH1212OO66 = ____ grams = ____ grams

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Mole - ParticlesMole - Particles1.1. Calculate the # of moles contained in Calculate the # of moles contained in

4.70 x 104.70 x 102424 atoms of calcium. atoms of calcium.

2.2. How many molecules of COHow many molecules of CO22 are are

contained in 4.56 moles of COcontained in 4.56 moles of CO22 ? ?

3.3. 0.025 mol of Ba = _____ atoms0.025 mol of Ba = _____ atoms

4.4. 1.75 x101.75 x102323 molecules NH molecules NH33 = ____ mol. = ____ mol.

5.5. 1.75 mol NaCl = _____ formula units1.75 mol NaCl = _____ formula units

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Mass - ParticleMass - Particle1.1. How many grams of water are How many grams of water are

contained in 5.87 x 10contained in 5.87 x 102222 molecules? molecules?

2.2. Convert 122 g of NaCl to formula units.Convert 122 g of NaCl to formula units.

3.3. 86.0 g of CO86.0 g of CO22 = _____ molecules = _____ molecules

4.4. How many atoms of silicon are How many atoms of silicon are contained in a 37.9 g sample of contained in a 37.9 g sample of silicon?silicon?

• Mole Song

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What is Avogadro’s favorite What is Avogadro’s favorite movie?movie?

Two Ways to Find Molar Mass

1. Use the periodic table Ex: What is the molar mass of C4H10?

58 g2. Using the formula

moles

gramsMM

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1.1. Calculate the molar mass of a Calculate the molar mass of a compound if 0.0392 mol of the compound if 0.0392 mol of the compound has a mass of 6.54 g.compound has a mass of 6.54 g.

2.2. If 5.22 x10If 5.22 x102424 atoms of an unknown atoms of an unknown element has a mass of 1032 g, what element has a mass of 1032 g, what is the element?is the element?

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Chemical EquivalentsChemical Equivalents Equal molesEqual moles

1.1. Calculate the # grams of carbon that Calculate the # grams of carbon that are chemically equivalent to 16 g of are chemically equivalent to 16 g of sulfur.sulfur.

2.2. Calculate the # grams of As that are Calculate the # grams of As that are chemically equivalent to 50.0 g of Srchemically equivalent to 50.0 g of Sr

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From Compounds to ElementsFrom Compounds to Elements 1 1 moleculemolecule of C of C66HH1212OO66 contains: contains:

6 atoms of C6 atoms of C

12 atoms of H12 atoms of H

6 atoms of O6 atoms of O 1 1 molemole of C of C66HH1212OO66 contains: contains:

6 moles of C6 moles of C

12 moles of H12 moles of H

6 moles of O6 moles of O

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ExamplesExamples1. Given 1.25 x101. Given 1.25 x102424 molecules of molecules of

CC66HH1212OO66, calculate:, calculate:

A. moles of CA. moles of C66HH1212OO66

B. grams of CB. grams of C66HH1212OO66

C. grams of carbonC. grams of carbon

D. atoms of oxygenD. atoms of oxygen

E. atoms of hydrogenE. atoms of hydrogen

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ExamplesExamples2. Given: 50.0 g of (NH2. Given: 50.0 g of (NH44))22CrCr22OO77. .

Calculate :Calculate :

A. Number of atoms of oxygenA. Number of atoms of oxygen

B. Number of grams of hydrogen.B. Number of grams of hydrogen.

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ExamplesExamples3. How many atoms of carbon are there 3. How many atoms of carbon are there

in 1.23 moles of Cin 1.23 moles of C66HH1212OO66 ? ?

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ExamplesExamples4. Calculate the length of Al foil 4. Calculate the length of Al foil

needed to have 1.00 mole of Al. The needed to have 1.00 mole of Al. The density of Al is 2.70 g/cmdensity of Al is 2.70 g/cm33. The foil is . The foil is 30.5 cm wide and the height 30.5 cm wide and the height (thickness) is 0.00250 cm.(thickness) is 0.00250 cm.

Percent Composition

100% xcompound

element

g

g

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ExampleExample1. Calculate the percent composition of 1. Calculate the percent composition of

a compound that is 29.0 g of Ag with a compound that is 29.0 g of Ag with 4.30 g of S.4.30 g of S.

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ExamplesExamples2. Calculate the percent composition of 2. Calculate the percent composition of

CC22HH44..

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ExamplesExamples3. What is the percent composition of 3. What is the percent composition of

aluminum carbonate?aluminum carbonate?

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HydratesHydrates4) Calculate the % of water in 4) Calculate the % of water in

MgSOMgSO44∙ 7H∙ 7H22OO

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ExamplesExamples5) Calculate the % of carbon in C5) Calculate the % of carbon in C1212HH2222OO1111..

6) How many grams of carbon are 6) How many grams of carbon are contained in 75.0 g of Ccontained in 75.0 g of C1212HH2222OO1111??

7) (Honors) How many grams of 7) (Honors) How many grams of CC1212HH2222OO1111 are needed to have 50.0 g of are needed to have 50.0 g of

carbon?carbon?

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Empirical FormulaEmpirical Formula

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The Empirical FormulaThe Empirical Formula

The The lowestlowest whole number ratio of whole number ratio of elements in a compound. (Simplest elements in a compound. (Simplest formula)formula)

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ExamplesExamplesAre the following empirical formulas?Are the following empirical formulas?

1. N1. N22OO44

nono

2. NH2. NH33

yesyes

3. K3. K22SOSO44

yesyes

4. C4. C66HH1212OO66

nono

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Calculating Empirical FormulasCalculating Empirical Formulas

Assume you have 100 g of the Assume you have 100 g of the compound.compound.

The % = grams.The % = grams. Convert grams to moles. Convert grams to moles. Find lowest whole number ratio by Find lowest whole number ratio by

dividing by the smallest moles.dividing by the smallest moles.

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ExampleExample 1) Calculate the empirical formula of a 1) Calculate the empirical formula of a

compound composed of 38.67 % C, compound composed of 38.67 % C, 16.22 % H, and 45.11 %N.16.22 % H, and 45.11 %N.

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ExampleExample 2) Caffeine is 49.48% C, 5.15% H, 2) Caffeine is 49.48% C, 5.15% H,

28.87% N and 16.49% O. What is its 28.87% N and 16.49% O. What is its empirical formula?empirical formula?

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ExampleExample3) Calculate the empirical formula of a 3) Calculate the empirical formula of a

compound that contains 57.6% Sr, compound that contains 57.6% Sr, 13.8% P and 28.6% O.13.8% P and 28.6% O.

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Molecular FormulaMolecular Formula Real (actual) formula.Real (actual) formula.

Example: CExample: C66HH1212OO66 molecular formula for molecular formula for glucoseglucose

Empirical formula is CHEmpirical formula is CH22OO

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ExampleExample1) A compound has an empirical

formula of ClCH2 and a molar mass of 98.96 g/mol. What is its molecular formula?

2) A compound has an empirical formula of C6H8O and a molar mass of 290.0 g/mol. What is its molecular formula?

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ExampleExample3)Ibuprofen is 75.69 % C, 8.80 % H,

15.51 % O, and has a molar mass of about 206 g/mol. What is its molecular formula?

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HydratesHydrates Compounds that contain waterCompounds that contain water Anhydrous- without waterAnhydrous- without water Ex: MgSOEx: MgSO44∙7H∙7H22OO Magnesium sulfate heptahydrate Magnesium sulfate heptahydrate This is a common substance called This is a common substance called

epsom saltsepsom salts

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ExamplesExamples1) Calculate the % of water in :1) Calculate the % of water in :

A.A. SrClSrCl22∙6H∙6H22OO

B.B. ZnSOZnSO44∙7H∙7H22OO

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ExamplesExamples2) 3.50 g of Na2) 3.50 g of Na22COCO33∙∙xxHH22O was heated to O was heated to

drive off the water. After heating, drive off the water. After heating, 1.30 g of the anhydrous compound 1.30 g of the anhydrous compound remained. Calculate:remained. Calculate:

A.A. % H % H22OO

B.B. Formula of the hydrate Formula of the hydrate