Introduction to Mass Stoichiometry

Intro to Stoichiometry

​Day 1

Mr Oglesby

​What is Stoichiometry

• ​Based on the Law of Conservation of mass

• ​It's about the QUANTITATIVE (How much) relationships between the amounts of reactants used and the amounts of products formed.

​Go to Youtube and input this link...

​https://youtu.be/7ln4DSfFGak

​Moles & Molar Mass - Just when you thought you were done with it :)

​Avogadro's Number - 6.02 x 10²³ atoms/mole

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​1 mole of any element or compound has 6.02x10²³ atoms or molecules

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​But each atom or molecule has a different mass

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​Molar Mass - the mass of a mole of an element is given by its atomic mass

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• ​The molar mass of carbon is 12.01 g/mole

• ​The molar mass of oxygen is 15.99 g/mole

• ​The molar mas of CO is 12.01 + 15.99 = 28.0 g/moleB

Multiple Choice

What do we call the mass of one mole?

• Atomic Number

• Molality

• Molarity

• Molar Mass

Multiple Choice

What is the molar mass of Potassium?

• 19

• 39.098 g/mole

• +1

• 209 g/mole

Multiple Choice

What is the molar mass of Bromine

• 79.90 g/mole

• 35

• -1

• 9.01 g/mole

Multiple Choice

What is the molar mass of Potassium bromide (KBr)

• 54

• 125.510 g/mole

• 119.002 g/mole

• +1

Multiple Choice

If you have one mole of elephants, how many moles of trunks and legs do you have?

• 4 moles of trunks and 4 moles of legs

• 1 mole of trunks and 1 mole of legs

• 1 mole of trunks and 4 moles of legs

• 2 moles of trunks and 1 mole of legs

Multiple Choice

In the balanced chemical equation to the left, how many moles of water are produced by reacting 1 mole of methane (CH₄) with 2 moles of O₂

• 2 moles

• 1 mole

• Mole Who?

• 6.02 x 10²³

​Mole Ratio's

​Mole Ratio's are a ratio between the numbers of molews of any two of the substances in a balanced chemical equation.

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​CH₄ + 2O₂ --> CO₂ + 2H₂O

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​The mole ratio between CH₄ / O₂ = 1/2

​The mole ratio between CH₄ / CO₂ = 1/1

​the mole ratio between CH₄ / H₂O = 1/2

​The mole ratio between O₂ / H₂O = 2/2.

​A mole is an amount. Kind of like a recipe....

​2 cups Flour + 1 cup oil + 1 cup buttermilk ---> 12 biscuits

Multiple Choice

2 cups Flour + 1 cup oil + 1 cup buttermilk ---> 12 biscuits

How many cups of flour do I need to make 12 biscuits?

• 1 cup

• 2 cups

• 4 cups

• I don't like biscuits

Multiple Choice

2 cups Flour + 1 cup oil + 1 cup buttermilk ---> 12 biscuits

If I only have 1 cup of flour, how much oil and buttermilk will I need, and how many biscuits can I make?

• 1 cup oil

  1 cup buttermilk

  12 biscuits

• 1/2 cup oil

  1/2 cup buttermilk

  6 biscuits

• 2 cups oil

  1 cup buttermilk

  24 biscuits

• I still don't like biscuits

Multiple Choice

2 cups Flour + 1 cup oil + 1 cup buttermilk ---> 12 biscuits

I have all the ingredients I need. How many biscuts can I make if I have 6 cups of flour?

• 6 biscuits

• 24 biscuits

• 36 biscuits

• 12 biscuits

​It works the same with a balanced chem eqn

Multiple Choice

2H₂ + O₂ --> 2H₂O

How many moles of O2 will be required to react with 6 moles of H2 ?

• 1 mole O₂

• 4 moles O₂

• 3 moles O₂

• 8 moles O₂

​Back to YouTube

https://youtu.be/S6UQX7ZdkTg​

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​Now you are doing Stoichiometry!

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