Chemistry11TheMoleV

Name:Date:Block:

1. EmpiricalFormula2. PercentComposition

EmpiricalFormulaMolecularFormula:

Ex:

EmpiricalFormula:

Ex:

StructuralFormula:

Ex:

MolecularFormula EmpiricalFormulaP4O10 C10H22 C6H18O3 C5H12O N2O4

1.Vinegarisadilutesolutionofaceticacid.Themolarmassofaceticacidis60.06g/molandithasanempiricalformulaofCH2O.Whatisthemolecularformulaofaceticacid?2.AcompoundhasanempiricalformulaofC3H4.Whichofthefollowingarepossiblemolarmassesofthecompound?20g/mol,55g/mol,80g/mol,120g/mol.

Identifiesthe ofeachtypeofatom

hexane Cbl114thesimplestwhole ratioofatomsofeachelement

hexane th

Hshfwsthestructure ofthemoleculeI l l l lH C C C c C c HH H H H H H

2 13052 CsHi3 CzHbo

Hmo2 NOz

C 12.01g1m01 I 60.06g1m01H t.olglmoz o.gg0 16.00g1m01

CHzO 1 12.01 2 1.01 1 16.00 ZXCHzOzHy0T30.03g1m01

XXX sogimol114 3 12.01 4 1.01 4 o I

CbHg40.07g1m01 120g1m01

40.0Cgt 12

3.AcompoundhasanempiricalformulaofCH2andamolarmassof42.09g/mol.Determineitsmolecularformula.4.Acompoundis48.65%carbon,8.11%hydrogenand43.24%oxygen.Determinetheempiricalformula.

Þ Thinkabouthaving100.0gofthesubstanceratherthanasa%...

Þ Convert%intomoles…

Þ Divideeachmolarquantitybythesmallestone

Þ Multiplybywhateverfactorisnecessarytogetawholenumberratio.5.Acompoundcontains9.93gC,58.6gCl,and31.4gF.Determineitsempiricalformula.

I 42.09g1m01CHz 1 12.01 2 1.01 74

14.03g1m01z CHz C3

o48.65g 8.11Gt 43.24go

C 48.65ft 405m01c

H 8.11gt.tog18.03mo1HO43.24gx1bIfg 2IIs0nauest

C405m012

ul 5Forevery1m01ofoxygen

H 803m01H theremustbe 15m01ofz

N carbonand3m01ofhydrogen

CtsHsO x2 IGHTC 9.93gxytz.nog

O 827m c smallest I C

Cl 58.6gxzts.mygl 65mo1c f z ngc 2 CI

F 31.4gxtgm.jogl65mol t.gs 1 n2F

CClzT

6.Asmallsampleofantifreezewasanalyzed.Itcontained4.51gC,1.13gHand6.01gO.Itwasdeterminedthatthemolarmassis62.0g/mol.Whatisthemolecularformulaofantifreeze?7.Ahydrocarbonisacompoundcontainingonlycarbonandhydrogen.Oneparticularhydrocarbonis92.29%carbonbymass.Ifthecompound’smolarmassis78.0g/molthenwhatisitsmolecularformula?PercentCompositionPercentComposition:

- Thepercentofacompound’smasscontributedbyeachtypeofatominthecompound.- Determinedfromtheformula.

8a.Findthepercentofcarbonbymassinethane,C2H6.8b.Findthepercentofhydrogenbymassinethane,C2H6.

EC 4.51 gx 0.376mole 1.12in

0.376 ol c o 3Ho1.139 112m01H smallest Empirical6Olgx 0.376nolo T Ct

Mylar Mass CHso12.01 1 3 1.01 Hoo

2 6 z31.04gal

7 684moleC 92.29gxg7.684mole

Ff Empirically

go

7.715 1LIg 7.63molHMolarmass 12.01 1 1.01 1

13.02gImo ld

6xkH C t 7f sY 6

Molar mass CzHoo 2 12.01 6 1.01 3008g1m01C 2 12.01 24.02 gImoI

motarnassdc 32o4

gg Yxloo f79.85TJtotal

100 79.851 20.157

H 6 1.01 606gImo I

molarmassdtt.bz bgsgY Hoo 420.157total

9.WhatisthepercentcompositionofeachtypeofasugarwiththeformulaC12H22O11?Practice:

10. Calculatethe%compositionofthefollowingcompounds:

a. FeCl2

b. C2H4O2

c. CaCl2.2H2O

d. (NH4)3PO4

e. NaOH

f. Ag(NH3)2Cl

g. K3Fe(CN)6

h. CaCO3

11. Calculatethe%oftheboldspeciesinthefollowingcompounds:

a. CaCl2.2H2O

b. Al2(SO4)3.18H2O

c. Cr(NH3)6Cl3.H2O

d. Fe2(SO4)3.9H2O

e. Cu(C2H3O2)2.2NH3

f. NiSO4.7H2

1.C2H4O22.80g/moland120g/mol3.C3H64.C3H6O25.CCl2F26.C2H6O27.C6H68a.79.85%b.20.15%9.42.098%C,6.491%H,51.411%O10a.Fe:44.06%Cl:55.94%b.C:39.99%H:6.73%O:53.28%c.Ca:27.26%Cl:48.22%H:2.75%O:21.77%d.N:28.19%H:8.13%P:20.77%O:42.92%e.Na:57.48%O:40.00%H:2.53%f.Ag:60.81%N:15.79%H:3.42%Cl:19.98%g.K:35.62%Fe:16.96%C:21.88%N:25.53%h.Ca:40.04%C:12.00%O:47.96%11a.24.51%b.48.66%c.36.70%d.51.27%e.54.74%f.8.37%

Molarmass GzHzz0 12 12.01 22 1.01 11 16.00 342.34glmolC 12 12.01 M342.347 1

1001 42.09

H 232fz.lygYIY xloot 6 8 H 2decimal

0 11 16.00glmolplaces

342.3 11001 4102

O

O

O

O

O

O

O

10 a Fedz 126.75gImo b GH402 6006gImo1Fe 144.061177 C

439.9971cL 5594 7 H k73 7

O fb

153.2802c Cactz 21120 147.0291m01d Nha Po 149.12g1m01Ca 427.2617Jn 428.197J

Cl 448.221ft H 48.13 112H 12.7517 P 42077

70ya o t 42aze NaOH 40.00gImoI f Ag NHS zCl 177.40g1m01

Na 457.4877J Ag i t6o 8lAgJ440.001.0J

N 115.791J

H t 42.5312H 43.4211J

g KrsFe CN 329.27galCl

419.9ft135.621.1 h cacoz 100.09gImoI

ez

116.96 12Ca 440.041daL

C lzi.seJc 112.007

N 125.537J O 447.9610J

I a Cad z 2H2O 147.02g1m01

H2O 124.51 11207b Ak Soy 181120 66653g1m01H2o C3 t 001148.6614

c Cr NH3 6C13H2O 278.61g1m01NHz 6

124 1.5418 1.0 136.707Mtd Fez 50413 91120 562 09gImo1

soy 3 32.07 12 16.00151.275047562 09

e Cu CaHzOz z 2MHz 215.73gImoI

CzH30z 4 i 054.74 CzHs

f Nisoy 7th 168.90gImo I

H Y f f837