Unit 5 Unit 6 The mole Analytical stoichiometry Lundquist -- 2015

The Mole Unit 5.1

Story time with L

What would happen if you had a mole (unit of measurement) of moles (the small furry animals)? YAY Chemistry! And physics And gore

Definitions Mole (mol) A unit Just a number like: “dozen” is 12 “pair” is 2 “gross” is doz dozens so 144 “ream” is 500 A mole is 602,214,129,000,000,000,000,000 of something (usually written 6.022×1023) Used to count molecules, which there are a lot of

Definitions 1 mole Close the number of atoms in 1 g of hydrogen ~the number of grains of sand on earth

A mole A burrowing mammal Not always pretty So what would 602,214,129,000,000,000,000,000 animals look like?

Wild approximations A moleanimal is small enough to throw, lets call it 1lb 1lb is 1kg (not really but sure) 602,214,129,000,000,000,000,000 is twice as long a trillion so 1 trillion trillions Planets weight about 1 trillion trillions

Better numbers An eastern mole (Scalopus aquaticus) weighs about 75 grams (6.022×1023)×75g≈4.52×1022kg 1 mole of moles = ½ moon

How much space does that take up? Mammals are MOSTLY water 1kg water = 1L water so 4.52×1022 kg = 4.52×1022 L The cube root of 4.52×1022 liters is 3,562 kilometers a sphere with a radius of 2,210 km a cube 2,213 miles on each edge

RELEASE the moles! Released onto the Earth’s surface, they’d fill it up to 80 kilometers deep a smothering ocean of high- pressure meat that would wipe out most life on the planet doing this on Earth is definitely not an option

Moles on the moon! Well near it… Gravitational attraction would pull them into a sphere Slightly larger than the moon Meat doesn’t compress well

Life on the mole-moon (Moletopia)  surface gravity about one-sixteenth of earth ~Pluto ~70oF (27oC) at first Moderately warmer core

Oddities on the Moletopia Lots of energy Could feed earth for 30 billion years Internal pressure over 100MPa You’re currently sitting at ~0.1MPa Decomposition could heat the mole- planet to a boil

DRILL THE MOLE-MOON! Self-limiting decomposition Bacteria can’t survive over 60oC Interior would eventually form kerogen then oil

EWWWWW! Exterior fur-coating would insulate the interior Interior core would heat Causing eruptions of meat

Heat death Everything cools and Moletopia is no exception Freezes all the way through Form exotic forms of ice

Don’t worry it’ll take a while

The End YAY!

The mole 1 mole is 6.022 x 1023 1 mole = 6.022 x 1023 Use it like any conversion Examples: 0.5 mol is how many ions How many moles is 1.81 x 1024 atoms of gold?

Do p. 19

Mole Analogy Project Worth a test grade Create an analogy that breaks a mole down to a number less than 500 million (5x108) Ex: How much could I give ever person on Earth if I had a mole of pennies?

Molar Conversions Unit 5.2

Unit 5.1 Note Quiz Questions 1.

Atom Inventory Subscript Apply to what is DIRECTLY in front of them Coefficient Apply to the WHOLE molecule

Unit 5.2 Note Quiz Questions Hint: Both sides of the reaction must be equal 2. 3. 4.

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Which would weigh more?

Which would weigh more?

Early Chemistry Dalton was the first to make a table of relative masses Used hydrogen H doesn’t bond with metals Berzelius used oxygen as it bonds with most other elements Issues arose with understanding of isotopes 16O was used as the standard IUPAC developed the model used today in 1960, based off 12C Accounts for 98.9% of all carbons

Carbon-12 12C has a mass of EXACTLY 12 amu 12g of 12C contains 6.022x1023 atoms of C the masses on the periodic table are the mass of 1 mole of that element

Molar Mass the mass of 1 mole of a compound

Unit 5.2 Note Quiz Questions 7. 5. 6.

Conversions Mass to mole Mole to mass How many moles is in 9g H2O How much would 2.0mol CH4 weight?

Mole Conversions

Do p. 18

Example Problem A cup of Starbucks coffee contains 36.0g of sugar, house hold sugar is sucrose (C12H22O11). How many moles of sugar in a cup of coffee? How many molecules?

Do p. 16-17 Do p. 20-21

Unit 5.2 Note Quiz Questions 8. 9. 10.

Analytical chemistry Unit 6.1

Percent Composition You are 70% water The earth is 50% oxygen The sun is 75% hydrogen

Simple percent composition If a sample is 5.0 g and is found to contain 3.75g C, and the rest is H, what percent is C? What percent is H? % 𝐶 = 3.75𝑔𝐶 5.0𝑔 𝐶 𝑥 𝐻 𝑦 ×100=75 % 𝐶 % 𝐻 = 5.0𝑔−3.75𝑔𝐶 5.0𝑔 𝐶 𝑥 𝐻 𝑦 ×100= 1.25𝑔𝐶 5.0𝑔 𝐶 𝑥 𝐻 𝑦 ×100=25 % 𝐻

Percent Composition The percentage of a compounds mass of an element 𝐴 2 𝐵 3 % 𝐴 = 2𝐴 2𝐴+3𝐵 ×100

Unit 6.1 Note Quiz Questions 1. 2.

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Chemical Formulas Molecular Formulas Empirical formulas Actual number of each element present Used for covalent compounds Simplest ratio of one element to another Used for ionic compounds

Chemical Formulas Converting from empirical formulas to molecular formulas Since the formula is reduced by a whole number the mass is also reduced by a whole number Determine the whole number and you can find the molecular formula 4 P + 10 O 4(39.97) + 10 (16) 319.88g/mol 2 P + 5 O 2(39.97) + 5 (16) 159.94 g/mol 𝑬𝒎𝒑𝒊𝒓𝒊𝒄𝒂𝒍= 𝑨 𝒙 𝑩 𝒚 𝑴𝒐𝒍𝒆𝒄𝒍𝒖𝒍𝒂𝒓=( 𝑨 𝒙 𝑩 𝒚 )𝒏 𝒏= 𝑴 𝑴 𝒎𝒐𝒍𝒆𝒄𝒖𝒍𝒂𝒓 𝑴 𝑴 𝒆𝒎𝒑𝒊𝒓𝒊𝒄𝒂𝒍 𝑴𝒐𝒍𝒆𝒄𝒖𝒍𝒂𝒓= 𝑨 𝒏𝒙 𝑩 𝒏𝒚

Example: A compound with the empirical formula of CH2O has a molar mass of 180g/mol, what is it’s molecular formula?

Unit 6.1 Note Quiz Questions 3. 5. 4.

Unit 6.1 Note Quiz Questions 7. 8.

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When in doubt, burn it.

The Poem By Mrs. Freeman Percent to mass Mass to mole Divide by small Multiple till whole

Example A white powder is analyzed and found to contain 43.64% P and 56.36% O by mass. The compound has a molar mass of 283.88 g/mol. What are the compound’s empirical and molecular formulas?

Unit 6.1 Note Quiz Questions 9. 10.

Finish p. 12 Do p. 13, 14, & 15

Quiz next class Percent composition Find the empirical formula Find molar mass Find molecular formula 𝑀𝑀= 𝑚𝑎𝑠𝑠 𝑚𝑜𝑙

Chemical Equations Unit 6.2

Types of Chemical Reactions

Unit 6.2 Note Quiz Questions 1. 2. 3.

Unit 6.2 Note Quiz Questions 4. 5. 6.

Do p. 23 & 24

Balancing Chemical Reactions The Law of Conservation of Mass Matter cannot be created nor destroyed What you start with MUST equal what you end with When obeyed a reaction is said to be “balanced”

Balancing Chemical Reactions When balancing you may ONLY CHANGE COEFFICIENTS Altering subscripts changes the compound H2O ≠ H2O2

Balancing Chemical Reactions Ways to balance equations Atom inventory Pictures

Balancing Chemical Reactions Tips Keep polyatomic ions together H2SO4 + Ba(NO3)2  BaSO4 + HNO3

Balancing Chemical Reactions Tips Save anything elemental for last CH4 + O2  CO2 + H2O

Balancing Chemical Reactions Tips When stuck double EVERYTHING except what is giving you trouble C2H6 + O2  CO2 + H2O

Unit 6.2 Note Quiz Questions 8. 7.

Unit 6.2 Note Quiz Questions 10. 9.

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Writing chemical equations ALL about nomenclature Ionic compounds metals + nonmetals Uses charges Covalent compounds nonmetals only Prefixes tell you how many Watch out for Diatomics Br2 I2 N2 Cl2 H2 O2 F2 Sulfur trioxide is produced from the incomplete combustion of fossil fuels. It reacts with atmospheric water vapor to produce hydrogen sulfate, a key component in acid rain. Write the balanced chemical reaction for this process

Writing chemical equations “+” Reacts with Combines with And “” Produces Forms Makes “(s)” Any shape word solid “(l)” Liquid “(g)” Gas vapor Sulfur trioxide is produced from the incomplete combustion of fossil fuels. It reacts with atmospheric water vapor to produce hydrogen sulfate, a key component in acid rain. Write the balanced chemical reaction for this process

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THE END Test NEXT PERIOD! 25 MC you will need to 21 to get a 100 Multiple Choice homework due NEXT PERIOD! Test NEXT PERIOD! 25 MC you will need to 21 to get a 100 1 free response worth 10 points, you will need to earn 5 to get a 100