1 mole

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1 mole1 mole marbles = covers Earth to depth of 50 miles

Counting by weighingPurpose: Calculate the amount of pennies in the bag by weighing them. ( You may take the pennies out of the bag to weigh them, but do not count them)DataCalculationsAtoms are too small to count so we weigh an amount (mole) and calculate the numberAvogodroThe actual size of the molecule is not importantAvagadro concluded that equal volumes of gas have equal number of moleculesBy the way, nobody really knew what a molecule was at the timeSome words mean numbersPairDozenBakers dozenGrossReam

Mole1 mole = 6.02 x 1023 representative particles(atoms)(molecules)(formula units)

( the number of carbon-12 atoms in 12.00 g)Atomic mass unitsWe measure atoms in atomic mass unitsAtomic mass unit = AMU = 1.66x10-27 KgIt is defined as 12 for Carbon 12Carbon 12 has six protons and six neutrons1 proton=1 amu (1.0078amu) 1 neutron= 1 amu (1.0087 amu)

Chemical MeasurementsAtomic MassThe weighted average of all the mass numbers for all the isotopes of the atom (a.m.u.)Formula MassThe sum of all the atomic masses for all atoms in the compound. (a.m.u.)

Calculate the atomic mass or formula massesNaClBr2NaClCO2Mg(OH)222.99 amu35.45 amu159.80 amu58.45 amu44.01 amu58.33 amu

Molar Mass=The mass of 1 mole( 6.02 x 1023) of representative particles=The atomic mass in g=The formula mass in gAtom, Molecule and IonsRepresentative particles smallest particle of that substanceSubstance Representative Particleelement atommolcular compound moleculeionic compoundformula unitCalculate the Molar massCaH2KNO3(NH4)2S

Remember1 mole = 6.02 x 1023 r.p.1 mole= molar mass(g)practiceDetermine the number of FU in .866 moles of AgNO3?

Find the mass of 0.98 moles of CaCl2.Molar VolumeThe volume of 1mole of a gas at standard temperature 0oCstandard pressure 1 atmosphere(pressure at sea level)

1 mole gas at STP = 22.4 LRemember1 mole = 6.02 x 1023 r.p.1 mole= molar mass(g)1 mole=22.4 L gasMultistep problemsHow many fu in 18.9 g NaCl?How many L in 4.5 x 1013 molecules Ne?

Solution= solute + solvent%mass= g solute g of solution

PPM = parts of solute 1,000,000 parts of solution

Molarity = Moles solute L of solution

Calculate1.What is the molarity if 13.5 g NaCl in 451 ml solution?2.How many g of KOH are in 3.5 L of a .67 M solution?3.How many ml of solution would you need to have 17.5 g of NaOH in a .35 M solution?Percent Composition% element = g element x 100% g total compoundFormulasEmpiricalsimplest whole number ratio

Molecular Formulaactual number of atoms in the formula

Practice:A compound has 13.5 g Ca10.8 g O.675 g HWhat is its empirical formula?

Try this oneWhat is the empirical formula that is 25.9% N , 74.1% OSpark1.How many moles of HCl are there in 1.00 liters of 2.0 molar HCl?2.How many milliliters of 13.2 g of HCL of a 3.4 M solution?3.How many oxygen atoms are in 150.2 mL of 2.00 M H2SO4?4.How many sulfur atoms are in 158.2 g of aluminum thiosulfate , Al2 (S2O3)3?

Molecular formulaSet up table:

Empircal Molecuar formulaMolar massA Chemical ReactionBalance the following reactionHydrogen and oxygen react to produce water

H2 + O2 H2O

2H2 + O2 2H2O

Why Do We Balance an Equation / Reaction?Makes it look prettyI do what Im toldHas something to do with conservationOf mass

Gas Has MassThe balanced equation says I shouldmix two hydrogens with one oxygenAnd then the reaction should go wellLets See!

So if.If the space between molecules is so largeand volume of gas at equal pressure and equal temperature have the same number of molecules

How can we compare things that are not gases?

MassWe would weigh it. Of course.But reactions go by numbers of molecules and atomsNot by mass, which is in gramsI wonder if there is a conversion factor?

How Can We Measure Atoms, the Darn Things are Too Small? We can compare the mass of atomsThis was done back in the 1800sHydrogen was found to be the smallest elementEverything was relative to HydrogenSo we can compare elements by using hydrogen as a standardConsider This About AtomsEach atom of hydrogen has 1.0 amu and uranium has 238 amu. Which has more atoms, one gram of H or one gram of U? Calcium has 40. amu per atom and helium has 4 amu per atom.Approximately how many times more atoms are in one gram of helium than in one gram of calcium?

WowSo if we can compare masses of atoms to each otherThen we could weigh them to get the proper proportion of them in a reactionWouldnt that be convenient?If only there were a conversion factor!