The Mole REVIEW OF TERMINOLOGY Atomic mass of

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The Mole

The Mole

REVIEW OF TERMINOLOGY

REVIEW OF TERMINOLOGY

Atomic mass of 1 atom in AMUs read from P. T. Atomic Mass C

Atomic mass of 1 atom in AMUs read from P. T. Atomic Mass C = 12. 011 AMU H = 1. 0079 AMU

Formula units represents a number of particles whether they are atoms, molecules or whole

Formula units represents a number of particles whether they are atoms, molecules or whole ionic compounds. Coefficients in a chemical reaction represent formula units E. g. 2 H 2 + 1 CH 4

Formula mass is mass in AMUs for one formula unit of a compound. Formula

Formula mass is mass in AMUs for one formula unit of a compound. Formula Mass of CH 4 = 16. 05 AMUs

However the AMU is not practical because it is TOO small. Also, how do

However the AMU is not practical because it is TOO small. Also, how do we relate AMUs to units we are familiar with like grams, pounds, liters, etc. .

The MOLE

The MOLE

A little history related to the development of the mole

A little history related to the development of the mole

While trying to find Chemical Formulas… Chemists Discovered a way of determining Atomic Masses

While trying to find Chemical Formulas… Chemists Discovered a way of determining Atomic Masses & the Mole

Chemists discovered that as long as temperature and pressure is kept constant gas rxns

Chemists discovered that as long as temperature and pressure is kept constant gas rxns had whole number ratio coefficients 2 L 1 L Hydrogen Nitrogen +1 L +3 L Oxygen Hydrogen Steam Ammonia

This helped determine chemical formulas as follows 2 L Hydrogen +1 L Oxygen Water

This helped determine chemical formulas as follows 2 L Hydrogen +1 L Oxygen Water So Water is H 2 O 1 1 L Nitrogen +3 L Hydrogen Ammonia So Ammonia is N 1 H 3

Avogadro realized that to find formulas from the volumes of gases used in a

Avogadro realized that to find formulas from the volumes of gases used in a chemical reaction you have to assume equal volumes of gasses contain the same number of gas particles H 2 O 2 Cl 2

In other words, 1 L of any gas has the same number of gas

In other words, 1 L of any gas has the same number of gas particles no matter what the composition of the gas.

That allowed chemists to find relative atomic masses

That allowed chemists to find relative atomic masses

Chemists took equal volumes of gases & weighed them to get the relative atomic

Chemists took equal volumes of gases & weighed them to get the relative atomic masses & created a new unit called Atomic Mass Unit (AMU).

So, relative atomic masses were developed: E. g. If Nitrogen weighs 14 times as

So, relative atomic masses were developed: E. g. If Nitrogen weighs 14 times as much as Hydrogen. 1 atom Nitrogen = 14 amu 1 atom Hydrogen = 1 amu

This is where the MOLE is created

This is where the MOLE is created

Chemists realized that they could keep the already established relative atomic masses, but could

Chemists realized that they could keep the already established relative atomic masses, but could change the unit to grams if they had enough volume. All that was needed was to find the volume to that would match the atomic masses measured in grams.

What they found is that 22. 4 L of a gas will allow you

What they found is that 22. 4 L of a gas will allow you to keep the numerical value of the atomic weight, but change the unit to grams. 22. 4 L He = 4 grams He

The Mole is Born 22. 4 L which was termed a MOLE is the

The Mole is Born 22. 4 L which was termed a MOLE is the amount of gas to make the AMUs convert directly to grams 22. 4 L N 2 = 1 mole N 2 = 28 g N 2

22. 4 L only works at S. T. P. Standard Temp and Pressure STP

22. 4 L only works at S. T. P. Standard Temp and Pressure STP is 25 °C and 1 atmosphere

22. 4 L H 2 @ STP = 1 mole H 2 = 2.

22. 4 L H 2 @ STP = 1 mole H 2 = 2. 01 g H 2 22. 4 L N 2 @ STP = 1 mole N 2 = 28. 0 g N 2 22. 4 L O 2 @ STP = 1 mole O 2 = 32. 0 g O 2 22. 4 L CO 2 @ STP = 1 mole CO 2 = 44. 0 g CO 2 22. 4 L Cl 2 @ STP = 1 mole Cl 2 = 71. 0 g Cl 2

Mole means Molecular Equivalent

Mole means Molecular Equivalent

NOTE!!: Mole is standing for a certain number of particles (atoms, molecules, formula units).

NOTE!!: Mole is standing for a certain number of particles (atoms, molecules, formula units). Chemists just did not know how many particles yet.

Through Mathematics & later confirmed by experimentation we found that. . .

Through Mathematics & later confirmed by experimentation we found that. . .

A mole is 6. 022 x 10 something. 23 of It is a name

A mole is 6. 022 x 10 something. 23 of It is a name for a number and the number of gas particles in 22. 4 L of a gas!!!!

6. 022 x is called 23 10 (NA) Avogadro’s Number

6. 022 x is called 23 10 (NA) Avogadro’s Number

DO WS – Molar Mass Lab – Molar Mass Methane

DO WS – Molar Mass Lab – Molar Mass Methane

Mole Conversions

Mole Conversions

The Mole is essential to chemical manufacturing because the mole links the atomic scale

The Mole is essential to chemical manufacturing because the mole links the atomic scale to the human scale atoms & molecules mass & volume

1 mol of a “X” is equal to …. . 22. 4 L X

1 mol of a “X” is equal to …. . 22. 4 L X = 1 mol X 23 = __ g X = 6. 02 x 10 X

You own a New Neon sign store and are making a sign that will

You own a New Neon sign store and are making a sign that will take 0. 50 L of Ne. You call a gas supplying store and Ne costs $100 for 100 g. The glass and electrical equipment cost $30. You charged $200 for the sign. Did you make or lose money on the sign?

So Again a Mole is ……. 1 mol __ = 6. 02 x 1023__

So Again a Mole is ……. 1 mol __ = 6. 02 x 1023__ = __ g__ and if it’s a gas the 1 mol ___ = 22. 4 L of _____ @ STP

Helpful reference chart

Helpful reference chart

Molecules F. U. s Atoms 1 mole 6. 02 x 1023 1 mole ?

Molecules F. U. s Atoms 1 mole 6. 02 x 1023 1 mole ? grams Moles 22. 4 L 1 mole 22. 4 L Volume (Liters) Mass (grams) ? grams 1 mole

Conversion Practice

Conversion Practice

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