Agriculture Chemistry

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Agriculture Chemistry

• Chapter 10

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Some food for thought

• If youre tyring to achieve, there will be
  roadblocks. Ive had them everybody has had
  them. But obstacles dont have to stop you. If
  you run into a wall, dont turn around and give
  up. Figure out how to climb it, go through it, or
  work around it. Michael Jordan
• Knowledge is Power Francis Bacon
• Pain is temporary. Quitting lasts forever. Lance
  Armstrong
• Age wrinkles the body. Quitting wrinkles the
  soul. Douglas MacArthur

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Learning Together

• If you are struggling with the content. Dont
  give up! Ask questions, do the homework, and
  repeat the practice problems we did in class!
• If you are understanding, well done! The best way
  to truly understand is to teach it! Help your
  peers, dont be silent and unhelpful.

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Conversion Challenge!
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Measuring Matter

• 3 ways to measure matter
• By count 1 dozen apples
• By mass 2.0 kg apples
• By volume .20 bushels apples
• 1 dozen apples 2.0kg apples 1 dozen apples
• 12 apples 1 dozen apples .20 bushel apples
• What is the mass of 90 average-sized apples if 1
  dozen of the apples has the mass of 2.0kg?

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• If .20 bushel is 1 dozen apples and a dozen
  apples has the mass of 2.0kg, what is the mass of
  .50 bushel of apples?

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• Assume 2.0 kg of apples is 1 dozen and that each
  apple has 8 seeds. How many apple seeds are in 14
  kg of apples?

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What is a Mole?

• To count representative particles in chemistry,
  we use the mole (mol).
• Representative particles atoms, molecules, or
  formula units.
• 1 mol 6.02 x 1023
• Called Avagadros number famous dead guy
• A mole of ANY substance is 6.02 x 1023
  representative particles
• 1 mol 6.02 x 1023 representative
  particles
• 6.02 x 1023 representative particle 1 mol

https//www.youtube.com/watch?vTEl4jeETVmg
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Question!!!

• How many representative particles are in
• A. a mole of water?
• B. a mole of Calcium?
• C. a mole of sugar?
• D. a mole of eggs?
• E. a mole of Copper(II) Sulfate?

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How large is a mole?

• 1 mole of marshmallows 18 miles high, covering
  Earths surface
• 1 mole of dollar bills
• to the moon and back 80 billion times

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The mass of a mole of an element

• 1 mole C atoms in 12g Carbon (6.02 x 1023)
• Atomic Mass in grams mass of 1 mole (6.02 x
  1023 atoms) of the element.
• Called Molar Mass, measured in grams per mole
  (g/mol).
• The Molar Mass of any two elements must contain
  the same atoms.
• 12.0g Carbon and 16.0g Oxygen have same atoms.
  (they just weigh different)
• Question How many atoms are contained in the
  molar mass of any element?

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Whats the molar mass of

• Nitrogen
• Phosphorus
• Potassium

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Lets try one!

• Iron is a common metal used in making
  agricultural implements. How many moles of Iron
  is 1.25 x 1023 atoms of Iron?
• Steps to Success
• 1st List Knowns and Unknowns
• 2nd Always write what youre given 1st
• 3rd Set up units so they cancel out and the end
  unit is on the top right
• 4th Do arithmetic

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You try!!!

• How many moles is 2.17 x 1023 representative
  particles of bromine?

• How many moles is 2.80 x 1024 atoms of silicon?

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Converting Moles to Number of Atoms

• Suppose you own a dairy and are curious about the
  methane emissions from your cows. You want to
  know how many atoms are in 2.12 mol of methane
  (CH4).
• Knowns
• -Number of moles 2.12 mol CH4
• -1 mol CH4 6.02 x 1023 molecules CH4
• -1 molecule CH4 5 atoms (1 carbon and 4
  hydrogen)
• -Desired conversion is moles gt molecules gt
  atoms
• Unknowns
• - atoms?
• Solve

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You Try

• How many atoms are in 1.14 mol SO3?

Sulfites are used in wine making and preserving
fruit!
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The mass of a mole of a compound

• Add atomic masses of atoms that make up a
  compound or molecule.
• Find Molar Mass of
• H20
• C6H12O6
• CH4
• Fe
• Ca

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You Try It!

• 1. Find the molar mass of PCl3

• 2. What is the mass of 1.00 mol of sodium
  hydrogen carbonate?

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Molar Mass Madness!

• Travel to each station and answer each problem
• Write down question and answer on piece of paper