Q3 Summary

• Each topic we covered will be reviewed one at a time.

• practice questions will follow each topic.

• Write notes/examples

3. The unit for molar mass is g/mol (#g = 1 mol)

4. We use this to convert between mass and moles

1. The mass of an element/ compound

2. Use the decimal number from the periodic table

Molar Mass is....

The molar mass of Cl (chlorine) would be

35.45 g/mol

35.45 g= 1 mol Cl

Calculating element

Calculating Compound

KNO₃

You need to find molar mass for each.

If there is more than one of that element, multply by that number

LINK

1. Mass to moles, moles to mass, you use..... MOLAR MASS

2. The unit for molar mass is g/mol ( connecting moles to mass)

3. #g is what you calculate

4. # moles is always 1

• Underline what you know/circle what you are looking for

• Start with what you know

• You want to cancel the unit you start with ..so... it goes to the....... BOTTOM

• The unit you circled is what goes on top

• Fill in your numbers

​Where to start

How many moles are in 20 g of Ca.

​

​Example

• You know- 20 g Ca

• You want to find- moles of Ca

• mass to moles, moles to mass, you use molar mass

• We start with what we know (20g) and we want to cancel that unit out.

• grams goes on the bottom

• what we are looking for goes on top (mols)

• Fill in NUMBERS

​

LINK

1. Use Avogadro's number to convert (6.02 X 10²³)

2. 1 mol = 6.02 X 10²³ molecules

   atoms

   particles

   formula units

• Underline what you know/circle what you are looking for

• Start with what you know

• You want to cancel the unit you start with ..so... it goes to the....... BOTTOM

• The unit you circled is what goes on top

• Fill in your numbers

​Where to start

How many atoms are in 5 moles of Zn

​

​Example

• You know- 5 mol Zn

• You want to find- atoms of Zn

• atoms tells you to use avogadro's number

• We start with what we know (5 mol) and we want to cancel that unit out.

• mole goes on the bottom

• what we are looking for goes on top (atoms)

• Fill in NUMBERS

​

LINK

5 types of reactions

LINK

• Start a table- list what you are starting with on each side.

• Your goal is to get both sides of the table to match by changing the COEFFIENTS

• As you add coefficients, update your table

​Where to start

​Example

• ​Make table

• Start with how many is on each side ( count the subscripts [small numbers])

• Add coefficients to balance each side

LINK

The equation connects each compound to each other

​Tells us the relationship of elements using a balanced chemcial equation

You must have 4 moles of NH₃ & 3 moles of O₂ to produce 2 moles of N₂ & 6 moles of H₂O

​Example

How many moles of O₂ are equal to 11 moles of NH₃

1. Under line what you know/circle what you are looking for

2. start with what you know

3. cancel out the unit you start with

4. Put unit you want on top

​Mole A to Mole B

LINK https://youtu.be/3zmeVamEsWI

The equation connects each compound to each other

​Tells us the relationship of elements using a balanced chemcial equation

You must have 4 moles of NH₃ & 3 moles of O₂ to produce 2 moles of N₂ & 6 moles of H₂O

​Example

1. Under line what you know/circle what you are looking for

2. start with what you know

3. cancel out the unit you start with

4. We have to do 2 steps to complete these

​Mole A to Mole B to Mass B

2 steps are required

LINK