2nd Sem M4 Chem Chapter 1

Atomic Mass and Mole

​Learning Objectives:

• Define the mole as a unit of measurement in chemistry and explain its importance.

• Differentiate between atomic mass and molar mass, and understand the relationship between them.

• Calculate molar mass of elements and compounds using atomic masses from the periodic table.

• Perform conversions between moles, mass, and number of particles (atoms, molecules).

​The Mole

Multiple Choice

Which of the following statements regarding the mole is NOT correct?

• 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

How many atoms of iodine are in a mole of iodine (I)?

• 53

• 63.55g

• 126.9

• 6.02 x 10²³

Multiple Choice

How can you figure out how particles (atoms) there are in 2 moles?

• 2

• 2 x (6.02 x 10²³)

• 2 x (atomic mass)

• 2 ÷ (6.02 x 10²³)

Multiple Choice

How many particles are found in a mole?

• $$6.022\ x\ 10^{23}$$  

• $$6.022\ x\ 1023$$  

• $$6022\ x\ 10^{23}$$  

• $$6022\ x\ 1023$$  

Multiple Choice

How many Carbon Atoms are in 4 moles of Carbon?

• 6.02 x 10²³

• 1.33 x 10²³

• 4.52

• 2.408 x 10²⁴

Multiple Choice

How many particles are there in 2 moles of carbon-12 atoms

• 2

• 6.02 x 10²³

• 3.01 x 10²³

• 1.204 x 10²⁴

Multiple Choice

How many atoms are there in 3 moles of carbon dioxide?

• 3

• 6.02 x 10²³

• 1.806 x 10²⁴

• 5.418 x 10²⁴

Multiple Choice

How many particles are there in 3 moles of Argon atoms

• 3

• 6.02 x 10²³

• 1.806 x 10²⁴

• 1.806 x 10²³

Multiple Choice

A mole = Avogadro's number = 6.022 x 10²³

• 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

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

The Mole Concept

By Guzman

Avogadro's Number & Molar Mass

​The mass of one mole of a substance is called Molar Mass (MM)

• Units are g​/mol

• In an element 1 mole is equal to its Atomic Mass​

Molar Mass

1 mole of atoms of any element will have a mass equal to its relative Atomic Mass

• Its shown in grams​

​Once Again

​1 Mol = 23 grams

2 Mol = 2 x 23 grams =

3 Mol = 3 x 23 grams =

​Examples

How many grams are in 2 mol of Carbon (C)?

1. Look for the element

2. Look at the atomic mass

3. multiply the mol they are asking for​

Multiple Choice

What are the units used for Molar Mass

• grams

• mols

• g/mol

• mol/g

Multiple Choice

How many grams are in 1 mole of Mg?

• 12 grams

• 24 grams

• 36 grams

• 6.022 x 10²³ grams

Multiple Choice

How many grams are in 3 mol of carbon?

• 6 grams

• 12 grams

• 18 grams

• 36 grams

Multiple Choice

How many grams are in 5 mol of lithium

• 3 grams

• 15 grams

• 35 grams

• 7 grams

Multiple Choice

How many grams are in 10 mol of fluorine?

• 19 grams

• 190 grams

• 90 grams

• 9 grams

Formula Weight

​Its the sum of all the atomic weights in a chemical formula.

to find the formula weight of a compound:

1. find the number of atoms of each element present in the compound

2. multiply the number of atoms by their respective weight

3. add the atomic weights of all the elements present.

Example: H₂O

1. H₂O contains 2 atoms of Hydrogen and 1 atom of Oxygen​

   ​

2. Hydrogen: 2 x 1.0080 = 2.016

Oxygen: 1 x 16 = 16

​

3. 2.016 + 16 = 18.016

Multiple Choice

what are the units used for Atomic Weight (Molecular Weight)?

• amu

• grams

• g/mol

• mol

Multiple Choice

Find the atomic weight (molecular weight) of Sugar - C₁₂H₂₂O₁₁

• 198.176 amu

• 342.308 amu

• 144.132 amu

• 29.019

Multiple Choice

Find the atomic weight (molecular weight) of Vitamin A - C₂₀H₃₀O

• 286.46 amu

• 240.22 amu

• 29.019 amu

• 129.46 amu

Multiple Choice

Find the atomic weight (molecular weight) of carbon monoxide - CO

• 16 amu

• 12.011 amu

• 28.011 amu

• 29.019 amu

Multiple Choice

Find the atomic weight (molecular weight) acetic acid - CH₃COOH

• 24.022 amu

• 31.035 amu

• 29.019 amu

• 60.054 amu

Putting these together

​Gram Formula Mass (Molar Mass)

• ​This is the combination of formula weight and mol

• Moles are used not only to describe elements, but compounds as well.

• When asked about the weight of 1 mol of a compound, you will follow the same steps as finding the molecular weight of your compound.​

• its units are g/mol​

​

Molar Mass

• molar mass = 1 mole

• CO₂

• C=12 , O₂ =16 x 2 = 32

• 12 + 32 = 44 g/mol

​Example

Determine the gram formula mass of each compound: KMnO₄

(this is asking for the mass of one mol of your compound)

​

K = 1 x 39.098 = 39.098

Mn = 1 x 54.938 = 54.938

O = ​4 x 16 = 64

= 158.036​ g/mol

Multiple Choice

What are the units used for Gram Formula Mass ?

• amu

• grams

• mol

• g/mol

Multiple Choice

Determine the gram formula mass of KCl

• 74.548 amu

• 35.45 amu

• 74.548 g/mol

• 35.45 g/mol

Multiple Choice

Molar Mass of CH₄

• 12 g/mol

• 16 g/mol

• 4 g/mol

Multiple Choice

Determine the gram formula mass (Molar Mass) of H₂SO₄

• 98.076 mol

• 98.076 g/mol

• 98.076 g

• 98.076 amu

Multiple Choice

CO₂ = 44 g/mol

How much would 3 moles of CO₂ equal?

• 132g/mol

• 33g/mol

• 404g/mol

Multiple Choice

Molar Mass of K₂CO₃

• 138.205 g/mol

• 35 g/mol

• 78.2 g/mol

Multiple Choice

Molar Mass of Ag₂O

• 231.7 g/mol

• 56.2 g/mol

• 734.4 g/mol

​Calculating moles, given mass (or inverse)

​Facts on The Mole

• 1 mole= 6.022 x 10²³ atoms

• The mole can either be a mass or a number of particles

• ​Abbreviation is 'mol'

• ​Commonly used term is molar mass = mass of one mole of a substance

  • has the units of g/mol or g.mol^-1

• We can easily convert between mass, moles, and particles

• We can also easily calcul​ate mass, molar mass, or moles (as long as we have two of these numbers)

​

Calculating number of particles, given ​moles (or inverse)

Multiple Choice

How many particles are there in 1 mole of oxygen gas?

[1st Hint: 1 molecule is counted as 1 particle]

• 1

• 6.02 x 10²³

• 1.204 x 10²⁴

• 12.04 x 10²³

Fill in the Blank

88 grams of H₂O (18 g/mol) is how many moles?

.

Fill in the Blank

52 grams of O₂ (Molar Mass = 32 g/mol) is how many moles?

.

Fill in the Blank

73 grams of AlBr₃ (267 g/mol) is how many moles?

.

Multiple Choice

800 grams of 2NH₃ (34 g/mol) is how many moles?

• 23.52 moles

• .0425 moles

• 834 moles

Multiple Choice

How many grams are in 3 mol of carbon?

• 6 grams

• 12 grams

• 18 grams

• 36 grams

​Examples

How many grams are in 2 mol of Carbon (C)?

1. Look for the element

2. Look at the atomic mass

3. multiply the mol they are asking for​

Chemical Formulas

Multiple Choice

How many different elements are present in the following chemical formula: CO₂

• 1

• 2

• 3

• 4

Multiple Choice

How many different elements are present in the following chemical formula: H₂SO₄

• 1

• 2

• 3

• 4

Multiple Choice

How many different elements are present in the following chemical formula: CoSO₄

• 1

• 2

• 3

• 4

Multiple Choice

How many different elements are present in the following chemical formula: K₂CO₃

• 1

• 2

• 3

• 4

Multiple Choice

How many different elements are present in the following chemical formula: Ag₂O

• 1

• 2

• 3

• 4

Multiple Choice

How many Hydrogen atoms are present in glucose: C₆H₁₂O₆

• 6

• 12

• 24

• 1

Multiple Choice

How many Oxygen atoms are present in H₂O?

• 1

• 2

• 3

• 4

Multiple Choice

How many Bromine atoms are present in AlBr₃?

• 1

• 2

• 3

• 4

Multiple Choice

How many Calcium atoms are present in CaCO₃?

• 1

• 2

• 3

• 4

Multiple Choice

How many Sulfur atoms are present in Na₂S0₄?

• 1

• 2

• 3

• 4

Multiple Choice

How many Sulfur atoms are in Cr(SO₄)₃?

• 1

• 3

• 4

• 12

Multiple Choice

How many Oxygen atoms are in Cr(SO₄)₃?

• 1

• 3

• 4

• 12

Multiple Choice

How many Chromium atoms are in Cr(SO₄)₃?

• 1

• 3

• 4

• 12

Multiple Choice

How many molecules of H₂O are present in: 3H₂O

• 1

• 2

• 3

• 4

Multiple Choice

How many atoms of Hydrogen are present in: 3H₂O

• 9

• 2

• 3

• 6

Multiple Choice

How many atoms of Oxygen are present in: 3H₂O

• 9

• 2

• 3

• 6

Multiple Choice

The elements in water are hydrogen and _________.

• chlorine

• oxygen

• nitrogen

• potassium

Fill in the Blank

How many total atoms are in the compound, 2Na(OH)₂?

Multiple Select

1. How many total atoms are in this compound?

2. How many atoms of Hydrogen are in C₆H₁₂O₆?

• 12 total atoms

• 24 total atoms

• 12 atoms of Hydrogen

• 24 atoms of Hydrogen

Fill in the Blank

How many total atoms are in 6H₂SO₄? (remember to add your parentheses and distribute).

Valence Electrons

• These are the number of ELECTRONS on the OUTER SHELL and they are responsible for how the atom BONDS to other atoms.

Multiple Choice

What are valence electrons?

• The total number of electrons in an atom

• The number of electrons in the outermost shell

• The number of electrons in the second shell

• The number of protons in the outermost shell

Multiple Choice

How many valence electrons does carbon have?

• 4

• 5

• 6

• 7

Multiple Choice

How many ELEMENTS are in this chemical equation?

• 3

• 4

• 9

• 10

Multiple Choice

Acetic acid is a compound found in vinegar. The chemical formula for acetic acid is CH₃COOH.

How many different ELEMENTS are in acetic acid?

• 3

• 5

• 6

• 8

Multiple Choice

All ____________ are made up of two or more atoms bonded together.

• atoms

• molecules

• electrons

• elements

Multiple Choice

The smallest unbreakable unit of a compound is called

• subscript
• proton
• formula
• molecule

The REACTANTS are the starting atoms. Basically the reactants mix together and REACT! The PRODUCTS are what you end up with after the chemical reaction occurs. The atoms rearrange to make something new. The something NEW are the PRODUCTS.

Use RAP to memorize which part of the chemical equation are the reactants and which part are the products

Multiple Choice

NaOH + HCl --> NaCl + H₂O Identify the reactants in the chemical equation above.

• NaOH and HCl

• NaCl and H₂O

• HCl and H₂O

• HCl and NaCl

Multiple Choice

2AgNO₃ + CaCl₂ --> 2AgCl + Ca(NO₃)₂

Identify the products in the chemical equation above.

• 2AgNO₃ and CaCl₂

• 2AgCl and Ca(NO₃)₂

• CaCl₂ and Ca

• Ag, Cl, N, and Ca

Multiple Choice

Cu + 2AgNO3 $$\longrightarrow$$ 2Ag + Cu(NO3)2 How many copper (Cu) atoms are there in  Cu(NO3)2 ?

• 1

• 2

• 5

• 6

Multiple Choice

How many MOLECULES are on the PRODUCT side of the chemical equation NaOH + HCl --> NaCl + H₂O

• 1

• 2

• 4

• 5

Poll

THE END

Did you learn anything today????

• Yes, I did and excited about learning more.

• No. I don't care about my grade.

• Yes, kinda. The holiday can't come any sooner!!!!

• Yes. I also like my science teacher and class.

Counting Atoms & Chemical Formulas

​

Multiple Choice

What elements are present in glucose, C₆H₁₂O₆?

• Calcium, Hydrogen, and Oxygen

• Carbon, Hydrogen, and Oxygen

• Carbon and Oxygen

• Calcium and Oxygen

Multiple Choice

How many carbon (C) atoms are present in glucose, C₆H₁₂O₆?

• 6

• 12

• 18

• 24

Multiple Choice

How many hydrogen (H) atoms are in glucose, C₆H₁₂O₆?

• 6

• 12

• 18

• 24

Multiple Choice

How many total elements make up glucose, C₆H₁₂O₆?

• 1

• 3

• 6

• 24

Multiple Choice

How many total atoms make up glucose, C₆H₁₂O₆?

• 3

• 6

• 12

• 24

Multiple Choice

How many atoms of potassium (K) are in 2 molecules of K₂SO₄?

• 1

• 2

• 4

• 8

Multiple Choice

How many atoms of sulfur (S) are in 2 molecules of K₂SO₄?

• 1

• 2

• 4

• 8

Multiple Choice

How many atoms of oxygen (O) are in 2 molecules of K₂SO₄?

• 1

• 2

• 4

• 8