The Mole

The Mole

6.02 X 1023#To play the movies and simulations included, view the presentation in Slide Show Mode.

AVOGADROS NUMBER AND MOLAR CONVERSIONSTEXTBOOK PAGE 224READ P 224 TO 228DO PRACTICE QUESTIONS 1 TO 4 PAGE 228#The MoleA counting unitSimilar to a dozen, except instead of 12, is 602,000,000,000,000,000,000,0006.02 X 1023 (in scientific notation)This number is named in honor of Amedeo AVOGADRO (1776 1856), who studied quantities of gases and discovered that no matter what the gas was, there were the same number of molecules present

#Just How Big is a Mole?Enough soft drink cans to cover the surface of the earth to a depth of over 200 miles. If you had Avogadro's number of unpopped popcorn kernels, and spread them across the United States of America, the country would be covered in popcorn to a depth of over 9 miles. If we were able to count atoms at the rate of 10 million per second, it would take about 2 billion years to count the atoms in one mole.

#The Mole1 dozen cookies = 12 cookies1 mole of cookies = 6.02 X 1023 cookies

1 dozen cars = 12 cars1 mole of cars = 6.02 X 1023 cars

1 dozen Al atoms = 12 Al atoms1 mole of Al atoms = 6.02 X 1023 atoms

Note that the NUMBER is always the same, but the MASS is very different!Mole is abbreviated mol (gee, thats a lot quicker to write, huh?)

#= 6.02 x 1023 C atoms= 6.02 x 1023 H2O molecules= 6.02 x 1023 NaCl molecules(technically, ionics are compounds not molecules so they are called formula units)6.02 x 1023 Na+ ions and 6.02 x 1023 Cl ionsA Mole of Particles Contains 6.02 x 1023 particles 1 mole C

1 mole H2O

1 mole NaCl# 6.02 x 1023 particles 1 mole or

1 mole6.02 x 1023 particles

Note that a particle could be an atom OR a molecule!

Avogadros Number as Conversion Factor#1. Number of atoms in 0.500 mole of Ala) 500 Al atoms b) 6.02 x 1023 Al atomsc) 3.01 x 1023 Al atoms

2.Number of moles of S in 1.8 x 1024 S atomsa) 1.0 mole S atomsb) 3.0 mole S atomsc) 1.1 x 1048 mole S atoms

Learning Check

#The Mass of 1 mole (in grams)Equal to the numerical value of the average atomic mass (get from periodic table) 1 mole of C atoms= 12.0 g1 mole of Mg atoms =24.3 g1 mole of Cu atoms =63.5 gMolar Mass#Other Names Related to Molar MassMolecular Mass/Molecular Weight: If you have a single molecule, mass is measured in amus instead of grams. But, the molecular mass/weight is the same numerical value as 1 mole of molecules. Only the units are different. (This is the beauty of Avogadros Number!)Formula Mass/Formula Weight: Same goes for compounds. But again, the numerical value is the same. Only the units are different.THE POINT: You may hear all of these terms which mean the SAME NUMBER just different units#Find the molar mass ( round to no decimals)Learning Check!1 mole of Br atoms1 mole of Sn atoms=80 g/mole= 119 g/mole#Mass in grams of 1 mole equal numerically to the sum of the atomic masses1 mole of CaCl2 = 111 g/mol 1 mole Ca x 40 g/mol + 2 moles Cl x 35.5 g/mol = 111 g/mol CaCl21 mole of N2O4 = 92 g/mol Molar Mass of Molecules and Compounds#Molar Mass of K2O = ? Grams/mole

B. Molar Mass of antacid Al(OH)3 = ? Grams/moleLearning Check!

#Prozac, C17H18F3NO, is a widely used antidepressant that inhibits the uptake of serotonin by the brain. Find its molar mass.Learning Check

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molar mass Grams Moles

Calculations with Molar Mass# Aluminum is often used for the structure of light-weight bicycle frames. How many grams of Al are in 3.00 moles of Al?3.00 moles Al ? g Al

Converting Moles and Grams#1. Molar mass of Al1 mole Al = 27.0 g Al2. Conversion factors for Al 27.0g Al or 1 mol Al 1 mol Al 27.0 g Al

3. Setup3.00 moles Al x 27.0 g Al 1 mole AlAnswer = 81.0 g Al# The artificial sweetener aspartame (Nutra-Sweet) formula C14H18N2O5 is used to sweeten diet foods, coffee and soft drinks. How many moles of aspartame are present in 225 g of aspartame?

Learning Check!

#Atoms/Molecules and GramsSince 6.02 X 1023 particles = 1 mole AND1 mole = molar mass (grams)You can convert atoms/molecules to moles and then moles to grams! (Two step process)You cant go directly from atoms to grams!!!! You MUST go thru MOLES.Thats like asking 2 dozen cookies weigh how many ounces if 1 cookie weighs 4 oz? You have to convert to dozen first!

# molar mass Avogadros number Grams Moles particles

Everything must go through Moles!!!Calculations#Atoms/Molecules and GramsHow many atoms of Cu are present in 35.4 g of Cu?35.4 g Cu 1 mol Cu 6.02 X 1023 atoms Cu 63.5 g Cu 1 mol Cu= 3.4 X 1023 atoms Cu

#Learning Check!How many atoms of K are present in 78.4 g of K?

#Learning Check!What is the mass (in grams) of 1.20 X 1024 molecules of glucose (C6H12O6)?

#Learning Check!How many atoms of O are present in 78.1 g of oxygen?78.1 g O2 1 mol O2 6.02 X 1023 molecules O2 2 atoms O 32.0 g O2 1 mol O2 1 molecule O2

#APRIL 11WHAT IS THE VOLUME OF A MOLE?#DO NOWFind the mass of the followingA) 1 mol of Ar (g)B) 1 mol of N2 (g)C) 1 mol of CO2 (g)

#MOLAR VOLUMEThe volume of a mole of any gas at STP is 22.4 liters.#Avogadros hypothesisEqual volumes of any gas at the same temperature an pressure contains the same number of molecules.

#April 12Stoichiometry problems

HOMEWORK Study page 302-305 in texbookDo practice questions 1 and 2 from page 304#Answers to Molar Volume PracticeCADBDCAC

ACBBDBCBD

#Set 1 Mole calculations34222 0.50 mol 781 g 8.40 g/ 58g/mol321414111g/ 44g/mol 0.8 mol#APRIL 15Objective: How to work with stoichiometric relationships? MOL TO MOL PROBLEMSDo nowWrite the equation for formation of Aluminum Oxide and balance it#STOICHIOMETRY- the study of the quantitative aspects of chemical reactions.

#ChallengeHow many mol of O2 are needed to produce 3 mol of Aluminum Oxide?

How many mol of Aluminum are needed?#Page 2281 . 1.13 x 10 23 ions of Na+8.73 x 10 6 atoms of As2.54 x 10 24 molecules3.6 x 10 24 formula units#Mass to mol problemsHow many mol of water can be produced if 6 g of H2 react with an excess of O2 ?HINT CONVERT THE GIVEN AMOUNT TO MOL!!!!!GivenUnknown#How many mol of C are needed to produce 88g of CO2?Convert given to mol!!!!GivenUnknown

#APRIL 16Objective: To practice mol to mol problems and to review for tomorrows testDO NOW : Read Mathematics of chemistry part 2 Stoichiometry and DO PROBLEMS 1 TO 8#TOPICS FOR TOMORROWS TEST% Composition hydratesBalancing chemical equationsRecognize types of chemical reactionsMole conversionsMol to mol problems#EXIT SLIPHow many mol of O2 are needed to produce 12 mol of H2O ?

4NH3+5O2 4 NO + 6 H2O#STOICHIOMETRY (mol problems)1- 5 mol H22- 1 mol F2O33- 3 mol FeCl34- 3.75 mol O25- 0.6 mol N26- 3.8 mol H27- 0.25 mol H28- 1.6 mol Zn#STOICHIOMETRIC RELATIONSHIP1 4.5 mol O22 0.2 mol Zn3 8 mol O24 6 mol H25 12 mol NH36 3 mol S7 2 mol AgCl#REVIEW SHEET ANSWERSACDDCBBACB 20. 4C 21. 4B 22. 4D 23. 3BA17. D18.419.1 #