Atoms and CompoundsAtoms and Compounds

ICS IIIICS III

Week 4Week 4

How to read the Periodic TableHow to read the Periodic Table

All Atoms Have MassAll Atoms Have MassMass numberMass number

The total number of protons and The total number of protons and neutrons in an elementneutrons in an element

Each proton and neutron have an Each proton and neutron have an average mass of about 1 amu (atomic average mass of about 1 amu (atomic mass unit)mass unit)

6 protons and 6 neutrons6 protons and 6 neutrons 12.01 or 1212.01 or 12

Atomic Mass UnitAtomic Mass UnitA weighted average mass of the A weighted average mass of the

atoms in a naturally occurring atoms in a naturally occurring samplesample

Practice with mass numbersPractice with mass numbers

What is the mass number for Sodium?What is the mass number for Sodium?22.99 or 2322.99 or 23

What is the mass number for Oxygen?What is the mass number for Oxygen?16.00 or 1616.00 or 16

What is the mass number for Hydrogen?What is the mass number for Hydrogen?1.01 or 11.01 or 1

Elements vs. CompoundsElements vs. Compounds

ElementElementSimplest form of matter.Simplest form of matter.Can not be broken downCan not be broken down

CompoundCompoundSubstance that contains two or more Substance that contains two or more

elements chemically combined in a fixed elements chemically combined in a fixed proportionproportion

Element vs. CompoundElement vs. Compound

OOThe element oxygenThe element oxygenOO22

The compound dioxide (two oxygen)The compound dioxide (two oxygen)Contains 2 oxygen elements bonded togetherContains 2 oxygen elements bonded together

Element vs. CompoundElement vs. Compound 2 Hydrogen elements (H) + 1 Oxygen (O) element 2 Hydrogen elements (H) + 1 Oxygen (O) element

HH22OO

1 Carbon elements (C) + 2 Oxygen (O) element 1 Carbon elements (C) + 2 Oxygen (O) element COCO22

How to find the molecular mass of How to find the molecular mass of a compounda compound

Molecular MassMolecular MassMolecular WeightMolecular Weight

All matter has All matter has mass, or weightmass, or weight

The sum of the The sum of the atomic masses of atomic masses of the atoms of each the atoms of each elementelement

•What is the molecular weight of CO2?

How to find the atomic mass of a How to find the atomic mass of a compoundcompound

COCO22

1 Carbon atom1 Carbon atom1 x 12 = 121 x 12 = 12

2 Oxygen atoms2 Oxygen atoms2 x 16 = 322 x 16 = 32

COCO22

12 + 32 = 4412 + 32 = 44

How to find the atomic mass of a How to find the atomic mass of a compoundcompound

Find the atomic mass of HFind the atomic mass of H22O.O.1818

Find the atomic mass of NaCl.Find the atomic mass of NaCl.5858

Find the atomic mass of CFind the atomic mass of C66HH1212OO66..180180

Mass of compoundsMass of compounds

16 17 18 36 2

Amount vs. WeightAmount vs. WeightSubstanceSubstance amountamount unitsunits weightweight

ApplesApples 1 dozen1 dozen 1212 555 grams555 grams

DonutsDonuts 1 dozen1 dozen 1212 250 grams250 grams

FeathersFeathers 1 dozen1 dozen 1212 5 grams5 grams

BricksBricks 1 dozen1 dozen 1212 10,000 g10,000 g

•What do all these substances have in common??

•Amount…… 1 dozen or 12 units

•Conversion factor?????????

•What is different about all these substances???

•The weight….

MoleMole

The number of atoms in 12 grams of The number of atoms in 12 grams of carbon-12.carbon-12.

The atomic mass of an element is the The atomic mass of an element is the weighted average of the mass of one mole weighted average of the mass of one mole of its atomsof its atoms

1 mole of a compound = atomic mass of 1 mole of a compound = atomic mass of the compoundthe compound

((MolMolar Mass)… ar Mass)… Mole Mass… Mass of one mole of compoundMole Mass… Mass of one mole of compound

What is a mole?What is a mole?

For example, the relative atomic mass of carbon is 12, so one mole of carbon atoms weighs 12 grams.

What is the mass of one mole of hydrogen atoms?

The term mole is used to talk about mass. One mole of a

substance is its relative atomic mass, or relative formula mass, in grams.

Molar MassMolar Mass

The atomic mass of an element or The atomic mass of an element or compound expressed in grams per molecompound expressed in grams per mole

Atomic mass goes hereAtomic mass goes here

CONVERSION FACTORCONVERSION FACTOR

Moles and MassMoles and Mass 1 mole of ______ has a molar mass of . . . . . . 1 mole of ______ has a molar mass of . . . . . .

2 grams of Hydrogen gas (H2 grams of Hydrogen gas (H22) = 1 mole of Hydrogen gas (H) = 1 mole of Hydrogen gas (H22))

16 g/mol 17 g/mol 18 g/mol 36.5 g/mol 2 g/mol

What is the mass of one mole?What is the mass of one mole?

MolesMoles

Beaker of WaterBeaker of WaterMass of water is 18 gMass of water is 18 gHow many moles??How many moles??

1 mole1 mole1 mole H1 mole H22O = 18 gO = 18 g

MolesMoles

Beaker of HClBeaker of HClMass of HCl is 36 gMass of HCl is 36 gHow many moles??How many moles??

1 mole1 mole1 mole HCl = 36 g1 mole HCl = 36 g

1 mole

18 g

1 mole

36 g

Amount vs. WeightAmount vs. WeightSubstanceSubstance amountamount unitsunits weightweight

ApplesApples 1 dozen1 dozen 1212 555 grams555 grams

DonutsDonuts 1 dozen1 dozen 1212 250 grams250 grams

FeathersFeathers 1 dozen1 dozen 1212 5 grams5 grams

BricksBricks 1 dozen1 dozen 1212 10,000 g10,000 g

•What do all these substances have in common??

•Amount…… 1 dozen or 12 units

•Conversion factor?????????

•What is different about all these substances???

•The weight….

MolesMoles

Beaker of WaterBeaker of WaterMass of water is 36 gMass of water is 36 gHow many moles??How many moles??

2 moles2 moles

CST QuestionsCST Questions

How many moles of carbon -12 are How many moles of carbon -12 are contained exactly 6 grams of carbon -12contained exactly 6 grams of carbon -12

1.1. 0.5 moles0.5 moles

2.2. 2.0 moles2.0 moles

3.3. 3.0 moles3.0 moles

4.4. 16.0 moles16.0 moles

1. What is the Molecular mass?

12 g/mole

2. Convert grams into moles

6 g Cx

12 g CH4

1 mole CH4-----------------

CST QuestionsCST Questions

How many moles of CHHow many moles of CH44 are contained in are contained in

96.0 grams of CH96.0 grams of CH44??

1.1. 3.00 moles3.00 moles

2.2. 6.00 moles6.00 moles

3.3. 12.0 moles12.0 moles

4.4. 16.0 moles16.0 moles

1. What is the Molecular mass?

16 g/mole

2. Convert grams into moles

96.0 g CH4 x

16 g CH4

1 mole CH4-----------------

How many moles?How many moles?