Mole Concept Presentation

7/27/2019 Mole Concept Presentation.

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The Mole

6.02 X 1023


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What is a mole?

A.) A blind furryanimal.

B.) A brown mark onyour body.

C.) An important

Chemistry concept. D.) All of these.


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Although a mole might be cute and fuzzy, we are goingto focus on the Chemistry concept.


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Counting Atoms Chemistry is a quantitative science - we need a

"counting unit."

The MOLE

1 mole is the amount of substance that contains asmany particles (atoms or molecules) as there are in

12g of Carbon-12.


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A mole is a counting unit.

Just like:12 eggs equals a dozen eggs

144 pencils equals one gross of pencils

2 socks equals a pair of socks.

500 sheets of paper equals one ream


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One mole equals 6.022 x 1023

particles

So one mole of eggs would be 6.022 x 1023

eggs One mole of pencils would be 6.022 x 1023 pencils

And so on...


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How Big is a Mole?One mole of marbles would cover the entire Earth(oceans included) for a depth of three miles!!!!

One mole of $100 bills stacked one on top of anotherwould reach from the Sun to Pluto and back 7.5 millionTimes!!!!

It would take light 9500 years to travel from thebottom to the top of a stack of 1 mole of $1 bills!!!!


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AvogadrosNumberAMOLE of any substance contains as many elementary units (atoms

and molecules) as the number of atoms in 12 g of the isotope ofcarbon-12.

This number is called AVOGADROs number NA= 6.02 x 1023

particles/mol

The mass of one mole of a substance is called MOLAR MASS Examples

H2 hydrogen 2 g/mol

He helium 4 g/mol

N2 nitrogen 28 g/mol

O2 oxygen 32 g/molCO2 carbon dioxide 44 g/mol


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What is all of this used for?

Avogadros constant can be used to convert an amountof moles into the equivalent number of atoms or grams.

This conversion is similar to changing 8 dozen eggs intothe number of individual eggs.


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The Mole 1 dozen cookies = 12 cookies

1 mole of cookies = 6.02 X 1023 cookies

1 dozen cars = 12 cars

1 mole of cars = 6.02 X 1023 cars

1 dozen Al atoms = 12 Al atoms

1 mole of Al atoms = 6.02 X 1023 atoms

Note that the NUMBER is always the same,but the MASS is very different!


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A Mole of Particles

Contains 6.02 x 1023 particles= 6.02 x 1023 C atoms

= 6.02 x 1023H2O molecules

= 6.02 x 1023NaCl molecules

6.02 x 1023 Na+ ions and

6.02 x 1023Cl ions

1 mole C

1 mole H2O

1 mole NaCl


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Using the mole concept is very much like using dozen.

Equivalence statement: 1 dozen eggs = 12 eggs

3.5 dozen eggs

1 dozen

12 eggs

( )( )= 42 eggs

How many eggs are in 3.5 dozen eggs?

3.5 mole Mg ( )( ) = 2.1X1024 Mg atoms

How many Mg atoms are in 3.5 moles of Mg?

Equivalence statement: 1 mole Mg = 6.022X10

23

Mg atoms

6.022X1023 Mg atoms

1 mole Mg


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Mole Calculations I How many sodium atoms are in 0.120 mol Na?

Step 1: we want atoms of Na

Step 2: we have 0.120 mol Na

Step 3: 1 mole Na = 6.02 1023 atoms Na

= 7.22 1022 atoms Na0.120 mol Na

1 mol Na

6.02 1023 atoms Na


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Mole Calculations I How many moles of potassium are in 1.25 1021 atoms K?

Step 1: we want moles K

Step 2: we have 1.25 1021 atoms K

Step 3: 1 mole K = 6.02 1023 atoms K

= 2.08

10-3

mol K1.25 1021

atoms K

1 mol K

6.02 1023 atoms K


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Molar Mass

The atomic mass of any substance expressed in grams is themolar mass(MM) of that substance.

The atomic mass of iron is 55.85 amu.

Therefore, the molar mass of iron is 55.85 g/mol.

Since oxygen occurs naturally as a diatomic, O2, the molar

mass of oxygen gas is 2 times 16.00 g or 32.00 g/mol.


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Learning Check

1. Number of atoms in 0.500 mole of Ala) 500 Al atomsb) 6.02 x 1023 Al atomsc) 3.01 x 1023 Alatoms

2.Number of moles of S in 1.8 x 1024 S atomsa) 1.0 mole S atomsb) 3.0 mole S atomsc) 1.1 x 1048 mole S atoms


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Calculating Molar Mass The molar mass of a substance is the sum of the molar masses

of each element.

What is the molar mass of magnesium nitrate, Mg(NO3)2?

The sum of the atomic masses is:

24 + 2(14 + 16 + 16 + 16) =

24 + 2(62) = 148 amu

The molar mass for Mg(NO3)2 is 148 g/mol.


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Mole Calculations II

Now we will use the molar mass of a compound to convertbetween grams of a substance and moles or particles of a

substance.

6.02 1023 particles = 1 mol = molar mass

If we want to convert particles to mass, we must first convert

particles to moles and than we can convert moles to mass.


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Mass-Mole Calculations

What is the mass of 1.33 moles of titanium, Ti? We want grams, we have 1.33 moles of titanium.

Use the molar mass of Ti: 1 mol Ti = 47.88 g Ti

= 63.7 g Ti1.33 mole Ti 47.88 g Ti

1 mole Ti


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Mole Conversions


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Its time for some mole jokes!

How does Avogadro talk to his friends?

By E-Mole! Hahaha

Where did Avogadro go on Saturday?The shopping mole.. Wow these are funny!

Why did Avogadro look forward to the year 2000?

It was the start of the new molennium!!!

What was Avogadro's favorite sport?

Golf - because he always got a mole-in-one.


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The End.

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Mole Concept Presentation