Molecular Chemistry Introduction

The
Mole

All about the Mole

(watch this)

Multiple Choice

What does a mole in chemistry measure?

• particles of a substance

• volume of a substance

• color of a substance

• density of a substance

The Mole

1 dozen =

1 gross =

1 ream =

1 mole =

12

144

500

6.02 x 10²³

There are exactly 12 grams of

carbon-12 in one mole of carbon-12.

Multiple Choice

Which one of the following units is used in a similar way to how the mole is used in chemistry?

• an inch

• a liter

• a dozen

• a mile

Definition of a mole

• A mole (mol) refers to Avogadro's number of particles of

any substance.

• 1 mole = 6.02 x 1023 particles (atoms, ions, molecules)

• 1 mole of an element = the average atomic mass of the

element from the periodic table (in grams)

• 1 mole of a compound = the sum of the masses of all

elements in the compound.

• 1 mole of a gas = 22.4 L

Multiple Choice

The picture shown is exactly one mole of sulfur, S, what is one mole a measurement of?

• the mass of sulfur

• the volume of sulfur

• the density of sulfur

• the number of particles of sulfur

Multiple Select

Which of the following statements regarding the mole is correct? Choose all CORRECT answers.

• A mole is a counting unit

• Equal to 6.02 x 10²³ particles.

• The concept of mole is similar to the concept of dozen

• none of the above

Multiple Choice

When comparing a mole of oxygen and a mole of sulfur, how many atoms does each have?

• oxygen has 16 grams of atoms

• sulfur has 32.06 grams of atoms

• both contains 6.02 x 10²³ atoms

• can not be determined

Multiple Choice

Which would have more atoms?

• 1 mole of Li

• 1 mole of Au

• 1 mole of Si

• None, all are equal

Multiple Choice

Which has more molecules?

• 1 mole H₂O

• 1 mole Al(OH)₃

• 1 mole NaCl

• There are all the same

Avogadro’s Number

6.02 x 10²³ is called “Avogadro’s Number” in
honor of the Italian chemist Amadeo Avogadro
(1776-1855).

Amadeo Avogadro

I didn’t discover it. Its

just named after me!

Multiple Choice

A mole = Avogadro's number = 6.02x10²³

• true

• false

Multiple Choice

The number 6.02 x 10²³ is called...

• Molar number

• Bohr's number
• Scientist's number

• Avogadro's number

Multiple Choice

How many atoms of iodine are in a mole of iodine?

• 6.02 x 10²⁵

• 602,000, 000

• 126.9

• 6.02 x 10²³

Multiple Choice

Which of the following statements regarding the mole is correct?

• A mole is a counting unit equal to 6.02 x 1023 particles.

• The number of particles in a mole is known as Avogadro’s number.

• 1 mole = Avogdro's number

• all of the above

Fill in the Blank

How many molecules of sugar (C₆H₁₂O₆) are in a mole?

.

^

Calculating molar mass

•1 mole of an element = the average atomic mass of the element
from the periodic table

•(in grams).

•Round periodic table masses to two decimal places

•Example: What is the molar mass of:

•

oxygen?

hydrogen?

sodium?

Drag and Drop

When comparing a mole of oxygen and a mole of sulfur, each substance has the same amount of grams in it.​ ​

Placeholder

Drag these tiles and drop them in the correct blank above

False

True

Calculating molar mass

• The subscripts in a chemical formula tell

you the number of moles of each element in
one mole of a compound.

• Example: 1 mole of H 2O2 contains ______

moles of H and _____ moles of O.

Calculating Formula Mass

Calculate the formula mass of carbon
dioxide, CO2.

12.01 g + 2(16.00 g) = 44.01 g

∴ One mole of CO2 (6.02 x 1023 molecules)
has a mass of 44.01 grams

Multiple Choice

How many moles of Oxygen are in sulfuric acid (H₂SO₄)?

• 8 moles

• 1 mole

• 4 moles

• 2 moles

Calculating molar mass

• To find the molar for a compound, multiply the subscript by the mass for
  that element, then add all masses together.

Example: H2O2

Example: Ca(NO3)2

​

Converting moles to grams

Calculations with Moles:

Calculations with Moles:

​

Converting grams to moles

• The particles in an element are the atoms that

make up the element.

• The particles in a compound are molecules or

ions.

• 1 mole of particles = 6.02 x 1023

particles

(atoms, molecules, ions)

​

Using Avogadro’s Number

Calculations with Moles:

​

Converting particles to moles

Calculations with Moles:

​

Converting moles to particles

Standard Molar Volume

Equal volumes of all gases at the same temperature
and pressure contain the same number of molecules.

-Amedeo Avogadro

At STP (Standard Temperature and Pressure):

1 mole of a gas occupies 22.4 liters of volume

​

At STP is:

Standard Temperature and Pressure

Calculations with Moles:

​

Converting liters to moles (@STP)

Calculations with Moles:

​

Converting moles to liters (@STP)

Multiple Choice

Which conversions factor would be used to convert moles to atoms

• Moles/atoms

• atoms/Moles

Multiple Choice

Which conversion factor would be used to convert liters to moles?

• Moles/Liters

• Liters/Moles

• grams/liters

• liters/grams

Multiple Choice

Which conversion factor would be used to convert moles to liters?

• 22.4 liters / 1 mole

• 1 Mole / 22.4 liters