SlideShare a Scribd company logo
The MOLE!!!
The MOLE!!!
People use words to represent specific
quantities all the time
Dozen eggs Pair of gloves Six-Pack
The MOLE!!!
1 mole = 6.02214199 x 1023
particles
1 mole = 6.02 x 1023
(the short form for mole is “mol”)
The MOLE!!!
1 mol = 6.02 x 1023
Called the Avogadro constant or
Avogadro’s number
(devised through experiments that
determined how many carbon atoms were
present in exactly 12 grams of carbon)
The MOLE!!!
1 mole = 602214199000000000000000 molecules
A very big
number!
The MOLE!!!
Converting moles to number of particles:
N = n X NA
Number of
particles
Number of
moles
Avogadro’s
number
The MOLE!!!
N = n X NA
A sample contains 1.25 mol of NO2.
a) How many molecules are in the
sample?
b) How many atoms are in the
sample?
The MOLE!!!
N = n X NA
a) A sample contains 1.25 mol of NO2.
How many molecules are in the
sample?
N = n X NA
N = (1.25mol) X (6.02 x 1023
molecules/mol)
N = 7.52 x 1023
molecules
.: there are 7.52 x 1023
molecules in 1.25 mol of NO2
The MOLE!!!
N = n X NA
A sample contains 1.25 mol of NO2.
b) How many atoms are in the sample?
(7.52 x 1023
molecules) x (3 atoms/molecule)
= 2.26 x 1024
atoms
.: there are 2.26 x 1024
atoms in 1.25 mol of NO2
The MOLE!!!
n = N
NA
Rearranging the formula…
How many moles are present in a sample of CO2
made up of 5.83 x 1024
molecules?
The MOLE!!!
n = N
NA
= (5.83 x 1024
molecules CO2)
(6.02 x 1023
molecules/mol)
How many moles are present in a sample of CO2
made up of 5.83 x 1024
molecules?
= 9.68 mol CO2
.: there are 9.68 mol of CO2 in the sample
MOLAR MASS
Molar mass of H =
1.0079 grams per mole
M = molar mass
Molar mass of Li =
6.941 grams per mole
MNa = 22.990g/mol
MOLAR MASS
Molar mass of compounds
MBeO = 9.01g/mol + 16.00g/mol
= 25.01g/mol
MCO = 12.01g/mol + 2x16.00g/mol
= 44.01g/mol
2
MOLAR MASS
m = n x M
m
n M
mass
Number of
moles
Molar mass
MOLAR MASS
A flask contains 0.750 mol of CO2. What mass of
CO2 is in this sample?
m = n x M
= (0.750mol) x (44.01g/mol)
GIVEN: n = 0.750mol
M = 12.01g/mol + 2 x 16.00g/mol
= 44.01g/mol
m = ?
= 33.0g
.: the mass of CO2 is 33.0g
MOLAR MASS
Rearranging the formula…
n = m
M
MOLAR MASS
How many moles of CH3COOH are in a 23.6g sample?
n = m
M
= (23.6g)/(60.06g/mol CH3COOH)
GIVEN: m = 23.6g
M = (2 x 12.01g/mol C) + (4 x 1.008g/mol H) + (2 x 16.00g/mol O)
= 60.06g
n = ?
= 0.393mol CH3COOH
.: there are 0.393mol of CH3COOH in 23.6g of CH3COOH
PERCENTAGE COMPOSITION
PERCENTAGE COMPOSITION
Law of Definite Proportions:
The elements in a compound are always present
in the same proportions by mass
Example:
Water = 11.2% hydrogen, 88.8% oxygen
MH2O = 18.016g/mol MH = 1.008g/mol
% of H in H2O = mass of H/mass of water
= (1.008g/mol x 2)/(18.016g/mol)
= 0.112  11.2%
PERCENTAGE COMPOSITION
A compound with a mass of 48.72g contains
32.69g of Zn & 16.03g of S. What is the percent
composition of the compound?
%Zn = 32.69g/48.72g
= 0.6710  67.10%
%S = 16.03g/48.72g
= 0.3290  32.90%
.: the percentage
composition for Zn is
67.10% and the
percentage composition
for S is 32.90%
EMPIRICAL FORMULA
A compound is 81.9% carbon, 6.12% hydrogen, and
12.1% oxygen by mass. What is the empirical
formula of the compound?
Molecular formula = Actual formula of compound
Empirical formula = simplest formula (shows the
lowest number ratio of the elements)
Example: Benzene
Molecular formula = C6H6
Empirical formula = CH
A compound is 81.9% carbon, 6.12% hydrogen, and
12.1% oxygen by mass. What is the empirical
formula of the compound?
STEP1: Assume the sample is 100g
STEP2: Find the number of moles of each element
STEP3: Divide all answers from STEP2 by the LOWEST
answer from STEP2
EMPIRICAL FORMULA
A compound is 81.9% carbon, 6.12% hydrogen, and
12.1% oxygen by mass. What is the empirical
formula of the compound?
STEP1: Assume the sample is 100g
So...
C = 81.9g H = 6.12g O = 12.1g
EMPIRICAL FORMULA
A compound is 81.9% carbon, 6.12% hydrogen, and
12.1% oxygen by mass. What is the empirical
formula of the compound?
STEP2: Find the number of moles of each element
C = 81.9g/12.01g/mol H = 6.12g/1.008g/mol
= 6.819mol = 6.0714mol
O = 12.1g/16.00g/mol
= 0.75625mol SMALLEST ANSWER
EMPIRICAL FORMULA
A compound is 81.9% carbon, 6.12% hydrogen, and
12.1% oxygen by mass. What is the empirical
formula of the compound?
STEP3: Divide all answers by the smallest answer
C = 6.819/0.75625 H = 6.0714/0.75625
= 9.0168 = 8.028
O = 0.75625/0.75625
= 1
EMPIRICAL FORMULA
A compound is 81.9% carbon, 6.12% hydrogen, and
12.1% oxygen by mass. What is the empirical
formula of the compound?
= C9H8O
C = 6.819/0.75625 H = 6.0714/0.75625
= 9.0168 = 8.028
O = 0.75625/0.75625
= 1
EMPIRICAL FORMULA
The empirical formula of ribose is CH2O. The molar
mass of this compound was determined to be
150g/mol. What is the molecular formula of ribose?
GIVEN: Empirical formula (1 C, 2 H, 1 O)
M = 150g/mol
MOLECULAR FORMULA
STEP1: Determine the molar mass of the empirical
formula
STEP2: Divide the given molar mass by your answer
from STEP1
STEP3: Multiply your empirical formula by your
answer from STEP2
The empirical formula of ribose is CH2O. The molar
mass of this compound was determined to be
150g/mol. What is the molecular formula of ribose?
MOLECULAR FORMULA
STEP1: Determine the molar mass of the empirical
formula
12g/mol + 2 x 1.008g/mol + 16g/mol = 30g/mol
STEP2: Divide the given molar mass by your answer
from STEP1
150g/mol / 30g/mol = 5
The empirical formula of ribose is CH2O. The molar
mass of this compound was determined to be
150g/mol. What is the molecular formula of ribose?
MOLECULAR FORMULA
C1x5H2x5O1x5 = C5H10O5
STEP3: Multiply your empirical formula by your answer
from STEP2
ANALYTICAL MACHINES FOR
CHEMISTRY
MASS SPECTROMETER
1) Upload sample
2) Same is vapourized
3) Sample is ionized
4) Ions accelerated by electric field
5) Detection to mass-to-charge ratio based on details of motion
6) Ions assorted according to mass-to-charge ratio
CARBON-HYDROGEN
COMBUSTION ANALYZER
1)Weigh H2O absorber and CO2 absorber before
experiment
2)Sample is burned
3)Absorbers are weighed again
CARBON-HYDROGEN COMBUSTION ANALYZER
A 1.000g sample of pure compound, containing
only carbon and hydrogen, was combusted in a
carbon-hydrogen combustion analyzer. The
combustion produced 0.6919g of water and 3.338g
of carbon dioxide.
a)Calculate the masses of the hydrogen and the
carbon
b)Find the empirical formula of the compound.
CARBON-HYDROGEN COMBUSTION ANALYZER
A 1.000g sample…The combustion produced 0.6919g of
water and 3.338g of carbon dioxide.
a) Calculate the masses of the hydrogen and the carbon
Mass of H = 2.02g/mol H2 x 0.6919g H2O
18.02g/mol H2O
= 0.07756g H2
This gives you the percent
composition of hydrogen in
water
Mass of C = 12.01g/mol C x 3.338g CO2
44.01g/mol CO2
= 0.9109g C
.: there was 0.0775g of H and 0.911g of C
always
0.112
always
0.27289
CARBON-HYDROGEN COMBUSTION ANALYZER
A 1.000g sample…The combustion produced 0.6919g of
water and 3.338g of carbon dioxide.
b) Find the empirical formula of the compound
Moles of H = 0.07756g
1.008g/mol
= 0.07694mol
Moles of C = 0.9109g
12.01g/mol
= 0.07584mol
SMALLEST ANSWEREmpirical formula = C0.07694/0.07584H0.07584/0.07584
= C1.0H1.0
= CH
.: the empirical formula is CH
HYDRATED SALTS
A 50.0g sample of Ba(OH)2·XH2O contains
27.2g of Ba(OH)2.
a)Calculate the percent, by mass, of water in
the sample
b)Find the value of X
HYDRATED SALTS
A 50.0g sample of Ba(OH)2·XH2O contains 27.2g of Ba(OH)2.
a) Calculate the percent, by mass, of water in the sample
= (total mass of sample) – (mass of Ba(OH)2 in sample) x 100%
(total mass of sample)
= 50.0g – 27.2g x 100%
50.0g
= 45.6%
.: the percent by mass of water is 45.6%
HYDRATED SALTS
A 50.0g sample of Ba(OH)2·XH2O contains 27.2g of Ba(OH)2.
b) Find the value of X
nH2O = m/M
= (50.0g – 27.2g)
(18.02g/mol)  this is the molar mass of H2O
= 1.27mol H2O
0.159/0.159 mol Ba(OH)2·1.27/0.159 mol H2O
Ba(OH)2·8H2O
nBa(OH)2 = m/M
= (27.2g)
(171.3g/mol)
= 0.159 mol Ba(OH)2SMALLEST ANSWER
.: X is 8

More Related Content

What's hot

Molalidad
MolalidadMolalidad
Molalidad
ElenaParedes13
 
Taller estequiometria
Taller estequiometriaTaller estequiometria
Taller estequiometria
SusanaEcheverri1
 
Problemas estequiometría 4º ESO v2
Problemas estequiometría 4º ESO v2Problemas estequiometría 4º ESO v2
Problemas estequiometría 4º ESO v2
Víctor M. Jiménez Suárez
 
Problema de reacción química ca co3 y h cl
Problema de reacción química ca co3 y h clProblema de reacción química ca co3 y h cl
Problema de reacción química ca co3 y h cl
Diego Martín Núñez
 
Ejerci. reac. 1º bac 13 14
Ejerci. reac. 1º bac 13 14Ejerci. reac. 1º bac 13 14
Ejerci. reac. 1º bac 13 14quimbioalmazan
 
Problema de reacción química cu y hno3
Problema de reacción química cu y hno3Problema de reacción química cu y hno3
Problema de reacción química cu y hno3
Diego Martín Núñez
 
Problemas de disoluciones (ii) 1º bac resueltos curso 13 14
Problemas de disoluciones (ii) 1º bac resueltos curso 13 14Problemas de disoluciones (ii) 1º bac resueltos curso 13 14
Problemas de disoluciones (ii) 1º bac resueltos curso 13 14quimbioalmazan
 
Mole calculations Made Easy
Mole calculations Made EasyMole calculations Made Easy
Mole calculations Made Easyrobertgist
 
Chapter 12 Stoichiometry
Chapter 12   StoichiometryChapter 12   Stoichiometry
Chapter 12 Stoichiometry
Galen West
 
Problema de reacción química zn y h cl
Problema de reacción química zn y h clProblema de reacción química zn y h cl
Problema de reacción química zn y h cl
Diego Martín Núñez
 
4 estequiometria s (1) estequiometria
4 estequiometria s (1) estequiometria4 estequiometria s (1) estequiometria
4 estequiometria s (1) estequiometria
Luisa Sanabria
 
Recuperación 2ª eval. química 2º bac 2013 2014
Recuperación 2ª eval. química 2º bac 2013 2014Recuperación 2ª eval. química 2º bac 2013 2014
Recuperación 2ª eval. química 2º bac 2013 2014quimbioalmazan
 
Reacciones con reactivo limitante
Reacciones con reactivo limitanteReacciones con reactivo limitante
Reacciones con reactivo limitante
Manuel Diaz
 
Chapter 7.4 : Determining Chemical Formulas
Chapter 7.4 : Determining Chemical FormulasChapter 7.4 : Determining Chemical Formulas
Chapter 7.4 : Determining Chemical FormulasChris Foltz
 
Estequiometria (1)
Estequiometria (1)Estequiometria (1)
Estequiometria (1)
enriquegarciaaties
 
estequiometría
estequiometríaestequiometría
estequiometría
kronologik0
 
Estequiometria
EstequiometriaEstequiometria
Estequiometria
Jorge Lezama
 

What's hot (20)

Molalidad
MolalidadMolalidad
Molalidad
 
Segunda serie
Segunda serieSegunda serie
Segunda serie
 
Taller estequiometria
Taller estequiometriaTaller estequiometria
Taller estequiometria
 
Problemas estequiometría 4º ESO v2
Problemas estequiometría 4º ESO v2Problemas estequiometría 4º ESO v2
Problemas estequiometría 4º ESO v2
 
Problema de reacción química ca co3 y h cl
Problema de reacción química ca co3 y h clProblema de reacción química ca co3 y h cl
Problema de reacción química ca co3 y h cl
 
Ejerci. reac. 1º bac 13 14
Ejerci. reac. 1º bac 13 14Ejerci. reac. 1º bac 13 14
Ejerci. reac. 1º bac 13 14
 
Problema de reacción química cu y hno3
Problema de reacción química cu y hno3Problema de reacción química cu y hno3
Problema de reacción química cu y hno3
 
Problemas de disoluciones (ii) 1º bac resueltos curso 13 14
Problemas de disoluciones (ii) 1º bac resueltos curso 13 14Problemas de disoluciones (ii) 1º bac resueltos curso 13 14
Problemas de disoluciones (ii) 1º bac resueltos curso 13 14
 
Mole calculations Made Easy
Mole calculations Made EasyMole calculations Made Easy
Mole calculations Made Easy
 
Chapter 12 Stoichiometry
Chapter 12   StoichiometryChapter 12   Stoichiometry
Chapter 12 Stoichiometry
 
Problema de reacción química zn y h cl
Problema de reacción química zn y h clProblema de reacción química zn y h cl
Problema de reacción química zn y h cl
 
4 estequiometria s (1) estequiometria
4 estequiometria s (1) estequiometria4 estequiometria s (1) estequiometria
4 estequiometria s (1) estequiometria
 
Recuperación 2ª eval. química 2º bac 2013 2014
Recuperación 2ª eval. química 2º bac 2013 2014Recuperación 2ª eval. química 2º bac 2013 2014
Recuperación 2ª eval. química 2º bac 2013 2014
 
Reacciones con reactivo limitante
Reacciones con reactivo limitanteReacciones con reactivo limitante
Reacciones con reactivo limitante
 
Chapter 7.4 : Determining Chemical Formulas
Chapter 7.4 : Determining Chemical FormulasChapter 7.4 : Determining Chemical Formulas
Chapter 7.4 : Determining Chemical Formulas
 
Principios de estequiometría
Principios de estequiometríaPrincipios de estequiometría
Principios de estequiometría
 
P gases
P gasesP gases
P gases
 
Estequiometria (1)
Estequiometria (1)Estequiometria (1)
Estequiometria (1)
 
estequiometría
estequiometríaestequiometría
estequiometría
 
Estequiometria
EstequiometriaEstequiometria
Estequiometria
 

Viewers also liked

18 percentage yield
18 percentage yield18 percentage yield
18 percentage yield
mrtangextrahelp
 
01 significant digits
01 significant digits01 significant digits
01 significant digits
mrtangextrahelp
 
17 stoichiometry
17 stoichiometry17 stoichiometry
17 stoichiometry
mrtangextrahelp
 
13 nuclear reactions
13 nuclear reactions13 nuclear reactions
13 nuclear reactions
mrtangextrahelp
 
10 naming and formula writing 2012
10 naming and formula writing 201210 naming and formula writing 2012
10 naming and formula writing 2012
mrtangextrahelp
 
11 balancing chemical equations
11 balancing chemical equations11 balancing chemical equations
11 balancing chemical equations
mrtangextrahelp
 
07 lewis dot diagrams
07 lewis dot diagrams07 lewis dot diagrams
07 lewis dot diagrams
mrtangextrahelp
 
09 polarity 2016
09 polarity 201609 polarity 2016
09 polarity 2016
mrtangextrahelp
 
04 periodic trends v2
04 periodic trends v204 periodic trends v2
04 periodic trends v2
mrtangextrahelp
 
08 lewis dot diagrams to 3 d diagrams
08 lewis dot diagrams to 3 d diagrams08 lewis dot diagrams to 3 d diagrams
08 lewis dot diagrams to 3 d diagrams
mrtangextrahelp
 
05 intramolecular bonds
05 intramolecular bonds05 intramolecular bonds
05 intramolecular bonds
mrtangextrahelp
 
Tang 02 wave quantum mechanic model
Tang 02   wave quantum mechanic modelTang 02   wave quantum mechanic model
Tang 02 wave quantum mechanic model
mrtangextrahelp
 
12 types of chemical reactions
12 types of chemical reactions12 types of chemical reactions
12 types of chemical reactions
mrtangextrahelp
 
04 periodic trends and effective nuclear charge supplement
04 periodic trends and effective nuclear charge supplement04 periodic trends and effective nuclear charge supplement
04 periodic trends and effective nuclear charge supplement
mrtangextrahelp
 
06 intermolecular forces
06 intermolecular forces06 intermolecular forces
06 intermolecular forces
mrtangextrahelp
 
Tang 04 periodic trends
Tang 04   periodic trendsTang 04   periodic trends
Tang 04 periodic trends
mrtangextrahelp
 
22 solution stoichiometry new
22 solution stoichiometry new22 solution stoichiometry new
22 solution stoichiometry new
mrtangextrahelp
 
22 acids + bases
22 acids + bases22 acids + bases
22 acids + bases
mrtangextrahelp
 
20 concentration of solutions
20 concentration of solutions20 concentration of solutions
20 concentration of solutions
mrtangextrahelp
 
19 solutions and solubility
19 solutions and solubility19 solutions and solubility
19 solutions and solubility
mrtangextrahelp
 

Viewers also liked (20)

18 percentage yield
18 percentage yield18 percentage yield
18 percentage yield
 
01 significant digits
01 significant digits01 significant digits
01 significant digits
 
17 stoichiometry
17 stoichiometry17 stoichiometry
17 stoichiometry
 
13 nuclear reactions
13 nuclear reactions13 nuclear reactions
13 nuclear reactions
 
10 naming and formula writing 2012
10 naming and formula writing 201210 naming and formula writing 2012
10 naming and formula writing 2012
 
11 balancing chemical equations
11 balancing chemical equations11 balancing chemical equations
11 balancing chemical equations
 
07 lewis dot diagrams
07 lewis dot diagrams07 lewis dot diagrams
07 lewis dot diagrams
 
09 polarity 2016
09 polarity 201609 polarity 2016
09 polarity 2016
 
04 periodic trends v2
04 periodic trends v204 periodic trends v2
04 periodic trends v2
 
08 lewis dot diagrams to 3 d diagrams
08 lewis dot diagrams to 3 d diagrams08 lewis dot diagrams to 3 d diagrams
08 lewis dot diagrams to 3 d diagrams
 
05 intramolecular bonds
05 intramolecular bonds05 intramolecular bonds
05 intramolecular bonds
 
Tang 02 wave quantum mechanic model
Tang 02   wave quantum mechanic modelTang 02   wave quantum mechanic model
Tang 02 wave quantum mechanic model
 
12 types of chemical reactions
12 types of chemical reactions12 types of chemical reactions
12 types of chemical reactions
 
04 periodic trends and effective nuclear charge supplement
04 periodic trends and effective nuclear charge supplement04 periodic trends and effective nuclear charge supplement
04 periodic trends and effective nuclear charge supplement
 
06 intermolecular forces
06 intermolecular forces06 intermolecular forces
06 intermolecular forces
 
Tang 04 periodic trends
Tang 04   periodic trendsTang 04   periodic trends
Tang 04 periodic trends
 
22 solution stoichiometry new
22 solution stoichiometry new22 solution stoichiometry new
22 solution stoichiometry new
 
22 acids + bases
22 acids + bases22 acids + bases
22 acids + bases
 
20 concentration of solutions
20 concentration of solutions20 concentration of solutions
20 concentration of solutions
 
19 solutions and solubility
19 solutions and solubility19 solutions and solubility
19 solutions and solubility
 

Similar to 14 the mole!!!

Chapter 10: The Mole
Chapter 10: The MoleChapter 10: The Mole
Chapter 10: The Molezehnerm2
 
PERCENTAGE COMPOSITION, EMPIRICAL AND MOLECULAR FORMULAS.ppt
PERCENTAGE COMPOSITION, EMPIRICAL AND MOLECULAR FORMULAS.pptPERCENTAGE COMPOSITION, EMPIRICAL AND MOLECULAR FORMULAS.ppt
PERCENTAGE COMPOSITION, EMPIRICAL AND MOLECULAR FORMULAS.ppt
ELMERBELZA
 
Chapter 7.3 : Using Chemical Formulas
Chapter 7.3 : Using Chemical FormulasChapter 7.3 : Using Chemical Formulas
Chapter 7.3 : Using Chemical FormulasChris Foltz
 
Ch 10 PPT...The Mole.pptx
Ch 10 PPT...The Mole.pptxCh 10 PPT...The Mole.pptx
Ch 10 PPT...The Mole.pptx
ChristianCatacutan2
 
Mole Concept
Mole ConceptMole Concept
Mole Concept
Jimnaira Abanto
 
Chapter 10 The Mole
Chapter 10 The MoleChapter 10 The Mole
Chapter 10 The Mole
Currituck County High School
 
Chemistry - Chp 10 - Chemical Quantities - PowerPoint
Chemistry - Chp 10 - Chemical Quantities - PowerPointChemistry - Chp 10 - Chemical Quantities - PowerPoint
Chemistry - Chp 10 - Chemical Quantities - PowerPointMr. Walajtys
 
Chapter8.ppt science 9*moleconceptslides
Chapter8.ppt science 9*moleconceptslidesChapter8.ppt science 9*moleconceptslides
Chapter8.ppt science 9*moleconceptslides
mantilejoshua05
 
Mole concept
Mole conceptMole concept
Mole concept
MussaOmary3
 
SHS STEM General Chemistry 1: Atoms, Moles, Equations, Stoichiometry
SHS STEM General Chemistry 1: Atoms, Moles, Equations, StoichiometrySHS STEM General Chemistry 1: Atoms, Moles, Equations, Stoichiometry
SHS STEM General Chemistry 1: Atoms, Moles, Equations, Stoichiometry
Paula Marie Llido
 
Chapter_3_Mass_Relationships.ppt
Chapter_3_Mass_Relationships.pptChapter_3_Mass_Relationships.ppt
Chapter_3_Mass_Relationships.ppt
IvyJoyceBuan2
 
Empirical_and_Molecular_Formulas.ppt
Empirical_and_Molecular_Formulas.pptEmpirical_and_Molecular_Formulas.ppt
Empirical_and_Molecular_Formulas.ppt
NickoRodolfo2
 
c4e237864d12cdb0be66e0e86247e4cben4.pptx
c4e237864d12cdb0be66e0e86247e4cben4.pptxc4e237864d12cdb0be66e0e86247e4cben4.pptx
c4e237864d12cdb0be66e0e86247e4cben4.pptx
manojkumartakshila
 
Mole Calculations Made Easy (old)
Mole Calculations Made Easy (old)Mole Calculations Made Easy (old)
Mole Calculations Made Easy (old)robertgist
 
Student Ch 9 The Mole
Student Ch 9 The MoleStudent Ch 9 The Mole
Student Ch 9 The Molejeanine
 
Chemicalcombinationsmoles,molecularandempirical
Chemicalcombinationsmoles,molecularandempiricalChemicalcombinationsmoles,molecularandempirical
Chemicalcombinationsmoles,molecularandempirical
Conferat Conferat
 
Chemistry - Chp 10 - Chemical Quantities - PowerPoint
Chemistry - Chp 10 - Chemical Quantities - PowerPointChemistry - Chp 10 - Chemical Quantities - PowerPoint
Chemistry - Chp 10 - Chemical Quantities - PowerPointMel Anthony Pepito
 

Similar to 14 the mole!!! (20)

14 the mole!!!
14 the mole!!!14 the mole!!!
14 the mole!!!
 
Ch 11 notes complete
Ch 11 notes completeCh 11 notes complete
Ch 11 notes complete
 
Ch 11 notes complete
Ch 11 notes completeCh 11 notes complete
Ch 11 notes complete
 
Chapter 10: The Mole
Chapter 10: The MoleChapter 10: The Mole
Chapter 10: The Mole
 
PERCENTAGE COMPOSITION, EMPIRICAL AND MOLECULAR FORMULAS.ppt
PERCENTAGE COMPOSITION, EMPIRICAL AND MOLECULAR FORMULAS.pptPERCENTAGE COMPOSITION, EMPIRICAL AND MOLECULAR FORMULAS.ppt
PERCENTAGE COMPOSITION, EMPIRICAL AND MOLECULAR FORMULAS.ppt
 
Chapter 7.3 : Using Chemical Formulas
Chapter 7.3 : Using Chemical FormulasChapter 7.3 : Using Chemical Formulas
Chapter 7.3 : Using Chemical Formulas
 
Ch 10 PPT...The Mole.pptx
Ch 10 PPT...The Mole.pptxCh 10 PPT...The Mole.pptx
Ch 10 PPT...The Mole.pptx
 
Mole Concept
Mole ConceptMole Concept
Mole Concept
 
Chapter 10 The Mole
Chapter 10 The MoleChapter 10 The Mole
Chapter 10 The Mole
 
Chemistry - Chp 10 - Chemical Quantities - PowerPoint
Chemistry - Chp 10 - Chemical Quantities - PowerPointChemistry - Chp 10 - Chemical Quantities - PowerPoint
Chemistry - Chp 10 - Chemical Quantities - PowerPoint
 
Chapter8.ppt science 9*moleconceptslides
Chapter8.ppt science 9*moleconceptslidesChapter8.ppt science 9*moleconceptslides
Chapter8.ppt science 9*moleconceptslides
 
Mole concept
Mole conceptMole concept
Mole concept
 
SHS STEM General Chemistry 1: Atoms, Moles, Equations, Stoichiometry
SHS STEM General Chemistry 1: Atoms, Moles, Equations, StoichiometrySHS STEM General Chemistry 1: Atoms, Moles, Equations, Stoichiometry
SHS STEM General Chemistry 1: Atoms, Moles, Equations, Stoichiometry
 
Chapter_3_Mass_Relationships.ppt
Chapter_3_Mass_Relationships.pptChapter_3_Mass_Relationships.ppt
Chapter_3_Mass_Relationships.ppt
 
Empirical_and_Molecular_Formulas.ppt
Empirical_and_Molecular_Formulas.pptEmpirical_and_Molecular_Formulas.ppt
Empirical_and_Molecular_Formulas.ppt
 
c4e237864d12cdb0be66e0e86247e4cben4.pptx
c4e237864d12cdb0be66e0e86247e4cben4.pptxc4e237864d12cdb0be66e0e86247e4cben4.pptx
c4e237864d12cdb0be66e0e86247e4cben4.pptx
 
Mole Calculations Made Easy (old)
Mole Calculations Made Easy (old)Mole Calculations Made Easy (old)
Mole Calculations Made Easy (old)
 
Student Ch 9 The Mole
Student Ch 9 The MoleStudent Ch 9 The Mole
Student Ch 9 The Mole
 
Chemicalcombinationsmoles,molecularandempirical
Chemicalcombinationsmoles,molecularandempiricalChemicalcombinationsmoles,molecularandempirical
Chemicalcombinationsmoles,molecularandempirical
 
Chemistry - Chp 10 - Chemical Quantities - PowerPoint
Chemistry - Chp 10 - Chemical Quantities - PowerPointChemistry - Chp 10 - Chemical Quantities - PowerPoint
Chemistry - Chp 10 - Chemical Quantities - PowerPoint
 

More from mrtangextrahelp

17 stoichiometry
17 stoichiometry17 stoichiometry
17 stoichiometry
mrtangextrahelp
 
22 acids + bases
22 acids + bases22 acids + bases
22 acids + bases
mrtangextrahelp
 
21 water treatment
21 water treatment21 water treatment
21 water treatment
mrtangextrahelp
 
22 acids + bases
22 acids + bases22 acids + bases
22 acids + bases
mrtangextrahelp
 
13 isotopes
13   isotopes13   isotopes
13 isotopes
mrtangextrahelp
 
04 periodic trends v2
04 periodic trends v204 periodic trends v2
04 periodic trends v2
mrtangextrahelp
 
09 lens applications
09   lens applications09   lens applications
09 lens applications
mrtangextrahelp
 
08 lens equations
08   lens equations08   lens equations
08 lens equations
mrtangextrahelp
 

More from mrtangextrahelp (10)

17 stoichiometry
17 stoichiometry17 stoichiometry
17 stoichiometry
 
23 gases
23 gases23 gases
23 gases
 
23 gases
23 gases23 gases
23 gases
 
22 acids + bases
22 acids + bases22 acids + bases
22 acids + bases
 
21 water treatment
21 water treatment21 water treatment
21 water treatment
 
22 acids + bases
22 acids + bases22 acids + bases
22 acids + bases
 
13 isotopes
13   isotopes13   isotopes
13 isotopes
 
04 periodic trends v2
04 periodic trends v204 periodic trends v2
04 periodic trends v2
 
09 lens applications
09   lens applications09   lens applications
09 lens applications
 
08 lens equations
08   lens equations08   lens equations
08 lens equations
 

Recently uploaded

Hemoglobin metabolism_pathophysiology.pptx
Hemoglobin metabolism_pathophysiology.pptxHemoglobin metabolism_pathophysiology.pptx
Hemoglobin metabolism_pathophysiology.pptx
muralinath2
 
GBSN- Microbiology (Lab 3) Gram Staining
GBSN- Microbiology (Lab 3) Gram StainingGBSN- Microbiology (Lab 3) Gram Staining
GBSN- Microbiology (Lab 3) Gram Staining
Areesha Ahmad
 
in vitro propagation of plants lecture note.pptx
in vitro propagation of plants lecture note.pptxin vitro propagation of plants lecture note.pptx
in vitro propagation of plants lecture note.pptx
yusufzako14
 
Observation of Io’s Resurfacing via Plume Deposition Using Ground-based Adapt...
Observation of Io’s Resurfacing via Plume Deposition Using Ground-based Adapt...Observation of Io’s Resurfacing via Plume Deposition Using Ground-based Adapt...
Observation of Io’s Resurfacing via Plume Deposition Using Ground-based Adapt...
Sérgio Sacani
 
Structures and textures of metamorphic rocks
Structures and textures of metamorphic rocksStructures and textures of metamorphic rocks
Structures and textures of metamorphic rocks
kumarmathi863
 
Unveiling the Energy Potential of Marshmallow Deposits.pdf
Unveiling the Energy Potential of Marshmallow Deposits.pdfUnveiling the Energy Potential of Marshmallow Deposits.pdf
Unveiling the Energy Potential of Marshmallow Deposits.pdf
Erdal Coalmaker
 
Mammalian Pineal Body Structure and Also Functions
Mammalian Pineal Body Structure and Also FunctionsMammalian Pineal Body Structure and Also Functions
Mammalian Pineal Body Structure and Also Functions
YOGESH DOGRA
 
Body fluids_tonicity_dehydration_hypovolemia_hypervolemia.pptx
Body fluids_tonicity_dehydration_hypovolemia_hypervolemia.pptxBody fluids_tonicity_dehydration_hypovolemia_hypervolemia.pptx
Body fluids_tonicity_dehydration_hypovolemia_hypervolemia.pptx
muralinath2
 
Circulatory system_ Laplace law. Ohms law.reynaults law,baro-chemo-receptors-...
Circulatory system_ Laplace law. Ohms law.reynaults law,baro-chemo-receptors-...Circulatory system_ Laplace law. Ohms law.reynaults law,baro-chemo-receptors-...
Circulatory system_ Laplace law. Ohms law.reynaults law,baro-chemo-receptors-...
muralinath2
 
The ASGCT Annual Meeting was packed with exciting progress in the field advan...
The ASGCT Annual Meeting was packed with exciting progress in the field advan...The ASGCT Annual Meeting was packed with exciting progress in the field advan...
The ASGCT Annual Meeting was packed with exciting progress in the field advan...
Health Advances
 
erythropoiesis-I_mechanism& clinical significance.pptx
erythropoiesis-I_mechanism& clinical significance.pptxerythropoiesis-I_mechanism& clinical significance.pptx
erythropoiesis-I_mechanism& clinical significance.pptx
muralinath2
 
Nucleic Acid-its structural and functional complexity.
Nucleic Acid-its structural and functional complexity.Nucleic Acid-its structural and functional complexity.
Nucleic Acid-its structural and functional complexity.
Nistarini College, Purulia (W.B) India
 
Deep Behavioral Phenotyping in Systems Neuroscience for Functional Atlasing a...
Deep Behavioral Phenotyping in Systems Neuroscience for Functional Atlasing a...Deep Behavioral Phenotyping in Systems Neuroscience for Functional Atlasing a...
Deep Behavioral Phenotyping in Systems Neuroscience for Functional Atlasing a...
Ana Luísa Pinho
 
extra-chromosomal-inheritance[1].pptx.pdfpdf
extra-chromosomal-inheritance[1].pptx.pdfpdfextra-chromosomal-inheritance[1].pptx.pdfpdf
extra-chromosomal-inheritance[1].pptx.pdfpdf
DiyaBiswas10
 
What is greenhouse gasses and how many gasses are there to affect the Earth.
What is greenhouse gasses and how many gasses are there to affect the Earth.What is greenhouse gasses and how many gasses are there to affect the Earth.
What is greenhouse gasses and how many gasses are there to affect the Earth.
moosaasad1975
 
Comparing Evolved Extractive Text Summary Scores of Bidirectional Encoder Rep...
Comparing Evolved Extractive Text Summary Scores of Bidirectional Encoder Rep...Comparing Evolved Extractive Text Summary Scores of Bidirectional Encoder Rep...
Comparing Evolved Extractive Text Summary Scores of Bidirectional Encoder Rep...
University of Maribor
 
Earliest Galaxies in the JADES Origins Field: Luminosity Function and Cosmic ...
Earliest Galaxies in the JADES Origins Field: Luminosity Function and Cosmic ...Earliest Galaxies in the JADES Origins Field: Luminosity Function and Cosmic ...
Earliest Galaxies in the JADES Origins Field: Luminosity Function and Cosmic ...
Sérgio Sacani
 
(May 29th, 2024) Advancements in Intravital Microscopy- Insights for Preclini...
(May 29th, 2024) Advancements in Intravital Microscopy- Insights for Preclini...(May 29th, 2024) Advancements in Intravital Microscopy- Insights for Preclini...
(May 29th, 2024) Advancements in Intravital Microscopy- Insights for Preclini...
Scintica Instrumentation
 
NuGOweek 2024 Ghent - programme - final version
NuGOweek 2024 Ghent - programme - final versionNuGOweek 2024 Ghent - programme - final version
NuGOweek 2024 Ghent - programme - final version
pablovgd
 
Orion Air Quality Monitoring Systems - CWS
Orion Air Quality Monitoring Systems - CWSOrion Air Quality Monitoring Systems - CWS
Orion Air Quality Monitoring Systems - CWS
Columbia Weather Systems
 

Recently uploaded (20)

Hemoglobin metabolism_pathophysiology.pptx
Hemoglobin metabolism_pathophysiology.pptxHemoglobin metabolism_pathophysiology.pptx
Hemoglobin metabolism_pathophysiology.pptx
 
GBSN- Microbiology (Lab 3) Gram Staining
GBSN- Microbiology (Lab 3) Gram StainingGBSN- Microbiology (Lab 3) Gram Staining
GBSN- Microbiology (Lab 3) Gram Staining
 
in vitro propagation of plants lecture note.pptx
in vitro propagation of plants lecture note.pptxin vitro propagation of plants lecture note.pptx
in vitro propagation of plants lecture note.pptx
 
Observation of Io’s Resurfacing via Plume Deposition Using Ground-based Adapt...
Observation of Io’s Resurfacing via Plume Deposition Using Ground-based Adapt...Observation of Io’s Resurfacing via Plume Deposition Using Ground-based Adapt...
Observation of Io’s Resurfacing via Plume Deposition Using Ground-based Adapt...
 
Structures and textures of metamorphic rocks
Structures and textures of metamorphic rocksStructures and textures of metamorphic rocks
Structures and textures of metamorphic rocks
 
Unveiling the Energy Potential of Marshmallow Deposits.pdf
Unveiling the Energy Potential of Marshmallow Deposits.pdfUnveiling the Energy Potential of Marshmallow Deposits.pdf
Unveiling the Energy Potential of Marshmallow Deposits.pdf
 
Mammalian Pineal Body Structure and Also Functions
Mammalian Pineal Body Structure and Also FunctionsMammalian Pineal Body Structure and Also Functions
Mammalian Pineal Body Structure and Also Functions
 
Body fluids_tonicity_dehydration_hypovolemia_hypervolemia.pptx
Body fluids_tonicity_dehydration_hypovolemia_hypervolemia.pptxBody fluids_tonicity_dehydration_hypovolemia_hypervolemia.pptx
Body fluids_tonicity_dehydration_hypovolemia_hypervolemia.pptx
 
Circulatory system_ Laplace law. Ohms law.reynaults law,baro-chemo-receptors-...
Circulatory system_ Laplace law. Ohms law.reynaults law,baro-chemo-receptors-...Circulatory system_ Laplace law. Ohms law.reynaults law,baro-chemo-receptors-...
Circulatory system_ Laplace law. Ohms law.reynaults law,baro-chemo-receptors-...
 
The ASGCT Annual Meeting was packed with exciting progress in the field advan...
The ASGCT Annual Meeting was packed with exciting progress in the field advan...The ASGCT Annual Meeting was packed with exciting progress in the field advan...
The ASGCT Annual Meeting was packed with exciting progress in the field advan...
 
erythropoiesis-I_mechanism& clinical significance.pptx
erythropoiesis-I_mechanism& clinical significance.pptxerythropoiesis-I_mechanism& clinical significance.pptx
erythropoiesis-I_mechanism& clinical significance.pptx
 
Nucleic Acid-its structural and functional complexity.
Nucleic Acid-its structural and functional complexity.Nucleic Acid-its structural and functional complexity.
Nucleic Acid-its structural and functional complexity.
 
Deep Behavioral Phenotyping in Systems Neuroscience for Functional Atlasing a...
Deep Behavioral Phenotyping in Systems Neuroscience for Functional Atlasing a...Deep Behavioral Phenotyping in Systems Neuroscience for Functional Atlasing a...
Deep Behavioral Phenotyping in Systems Neuroscience for Functional Atlasing a...
 
extra-chromosomal-inheritance[1].pptx.pdfpdf
extra-chromosomal-inheritance[1].pptx.pdfpdfextra-chromosomal-inheritance[1].pptx.pdfpdf
extra-chromosomal-inheritance[1].pptx.pdfpdf
 
What is greenhouse gasses and how many gasses are there to affect the Earth.
What is greenhouse gasses and how many gasses are there to affect the Earth.What is greenhouse gasses and how many gasses are there to affect the Earth.
What is greenhouse gasses and how many gasses are there to affect the Earth.
 
Comparing Evolved Extractive Text Summary Scores of Bidirectional Encoder Rep...
Comparing Evolved Extractive Text Summary Scores of Bidirectional Encoder Rep...Comparing Evolved Extractive Text Summary Scores of Bidirectional Encoder Rep...
Comparing Evolved Extractive Text Summary Scores of Bidirectional Encoder Rep...
 
Earliest Galaxies in the JADES Origins Field: Luminosity Function and Cosmic ...
Earliest Galaxies in the JADES Origins Field: Luminosity Function and Cosmic ...Earliest Galaxies in the JADES Origins Field: Luminosity Function and Cosmic ...
Earliest Galaxies in the JADES Origins Field: Luminosity Function and Cosmic ...
 
(May 29th, 2024) Advancements in Intravital Microscopy- Insights for Preclini...
(May 29th, 2024) Advancements in Intravital Microscopy- Insights for Preclini...(May 29th, 2024) Advancements in Intravital Microscopy- Insights for Preclini...
(May 29th, 2024) Advancements in Intravital Microscopy- Insights for Preclini...
 
NuGOweek 2024 Ghent - programme - final version
NuGOweek 2024 Ghent - programme - final versionNuGOweek 2024 Ghent - programme - final version
NuGOweek 2024 Ghent - programme - final version
 
Orion Air Quality Monitoring Systems - CWS
Orion Air Quality Monitoring Systems - CWSOrion Air Quality Monitoring Systems - CWS
Orion Air Quality Monitoring Systems - CWS
 

14 the mole!!!

  • 2. The MOLE!!! People use words to represent specific quantities all the time Dozen eggs Pair of gloves Six-Pack
  • 3. The MOLE!!! 1 mole = 6.02214199 x 1023 particles 1 mole = 6.02 x 1023 (the short form for mole is “mol”)
  • 4. The MOLE!!! 1 mol = 6.02 x 1023 Called the Avogadro constant or Avogadro’s number (devised through experiments that determined how many carbon atoms were present in exactly 12 grams of carbon)
  • 5. The MOLE!!! 1 mole = 602214199000000000000000 molecules A very big number!
  • 6. The MOLE!!! Converting moles to number of particles: N = n X NA Number of particles Number of moles Avogadro’s number
  • 7. The MOLE!!! N = n X NA A sample contains 1.25 mol of NO2. a) How many molecules are in the sample? b) How many atoms are in the sample?
  • 8. The MOLE!!! N = n X NA a) A sample contains 1.25 mol of NO2. How many molecules are in the sample? N = n X NA N = (1.25mol) X (6.02 x 1023 molecules/mol) N = 7.52 x 1023 molecules .: there are 7.52 x 1023 molecules in 1.25 mol of NO2
  • 9. The MOLE!!! N = n X NA A sample contains 1.25 mol of NO2. b) How many atoms are in the sample? (7.52 x 1023 molecules) x (3 atoms/molecule) = 2.26 x 1024 atoms .: there are 2.26 x 1024 atoms in 1.25 mol of NO2
  • 10. The MOLE!!! n = N NA Rearranging the formula… How many moles are present in a sample of CO2 made up of 5.83 x 1024 molecules?
  • 11. The MOLE!!! n = N NA = (5.83 x 1024 molecules CO2) (6.02 x 1023 molecules/mol) How many moles are present in a sample of CO2 made up of 5.83 x 1024 molecules? = 9.68 mol CO2 .: there are 9.68 mol of CO2 in the sample
  • 12. MOLAR MASS Molar mass of H = 1.0079 grams per mole M = molar mass Molar mass of Li = 6.941 grams per mole MNa = 22.990g/mol
  • 13. MOLAR MASS Molar mass of compounds MBeO = 9.01g/mol + 16.00g/mol = 25.01g/mol MCO = 12.01g/mol + 2x16.00g/mol = 44.01g/mol 2
  • 14. MOLAR MASS m = n x M m n M mass Number of moles Molar mass
  • 15. MOLAR MASS A flask contains 0.750 mol of CO2. What mass of CO2 is in this sample? m = n x M = (0.750mol) x (44.01g/mol) GIVEN: n = 0.750mol M = 12.01g/mol + 2 x 16.00g/mol = 44.01g/mol m = ? = 33.0g .: the mass of CO2 is 33.0g
  • 16. MOLAR MASS Rearranging the formula… n = m M
  • 17. MOLAR MASS How many moles of CH3COOH are in a 23.6g sample? n = m M = (23.6g)/(60.06g/mol CH3COOH) GIVEN: m = 23.6g M = (2 x 12.01g/mol C) + (4 x 1.008g/mol H) + (2 x 16.00g/mol O) = 60.06g n = ? = 0.393mol CH3COOH .: there are 0.393mol of CH3COOH in 23.6g of CH3COOH
  • 19. PERCENTAGE COMPOSITION Law of Definite Proportions: The elements in a compound are always present in the same proportions by mass Example: Water = 11.2% hydrogen, 88.8% oxygen MH2O = 18.016g/mol MH = 1.008g/mol % of H in H2O = mass of H/mass of water = (1.008g/mol x 2)/(18.016g/mol) = 0.112  11.2%
  • 20. PERCENTAGE COMPOSITION A compound with a mass of 48.72g contains 32.69g of Zn & 16.03g of S. What is the percent composition of the compound? %Zn = 32.69g/48.72g = 0.6710  67.10% %S = 16.03g/48.72g = 0.3290  32.90% .: the percentage composition for Zn is 67.10% and the percentage composition for S is 32.90%
  • 21. EMPIRICAL FORMULA A compound is 81.9% carbon, 6.12% hydrogen, and 12.1% oxygen by mass. What is the empirical formula of the compound? Molecular formula = Actual formula of compound Empirical formula = simplest formula (shows the lowest number ratio of the elements) Example: Benzene Molecular formula = C6H6 Empirical formula = CH
  • 22. A compound is 81.9% carbon, 6.12% hydrogen, and 12.1% oxygen by mass. What is the empirical formula of the compound? STEP1: Assume the sample is 100g STEP2: Find the number of moles of each element STEP3: Divide all answers from STEP2 by the LOWEST answer from STEP2 EMPIRICAL FORMULA
  • 23. A compound is 81.9% carbon, 6.12% hydrogen, and 12.1% oxygen by mass. What is the empirical formula of the compound? STEP1: Assume the sample is 100g So... C = 81.9g H = 6.12g O = 12.1g EMPIRICAL FORMULA
  • 24. A compound is 81.9% carbon, 6.12% hydrogen, and 12.1% oxygen by mass. What is the empirical formula of the compound? STEP2: Find the number of moles of each element C = 81.9g/12.01g/mol H = 6.12g/1.008g/mol = 6.819mol = 6.0714mol O = 12.1g/16.00g/mol = 0.75625mol SMALLEST ANSWER EMPIRICAL FORMULA
  • 25. A compound is 81.9% carbon, 6.12% hydrogen, and 12.1% oxygen by mass. What is the empirical formula of the compound? STEP3: Divide all answers by the smallest answer C = 6.819/0.75625 H = 6.0714/0.75625 = 9.0168 = 8.028 O = 0.75625/0.75625 = 1 EMPIRICAL FORMULA
  • 26. A compound is 81.9% carbon, 6.12% hydrogen, and 12.1% oxygen by mass. What is the empirical formula of the compound? = C9H8O C = 6.819/0.75625 H = 6.0714/0.75625 = 9.0168 = 8.028 O = 0.75625/0.75625 = 1 EMPIRICAL FORMULA
  • 27. The empirical formula of ribose is CH2O. The molar mass of this compound was determined to be 150g/mol. What is the molecular formula of ribose? GIVEN: Empirical formula (1 C, 2 H, 1 O) M = 150g/mol MOLECULAR FORMULA STEP1: Determine the molar mass of the empirical formula STEP2: Divide the given molar mass by your answer from STEP1 STEP3: Multiply your empirical formula by your answer from STEP2
  • 28. The empirical formula of ribose is CH2O. The molar mass of this compound was determined to be 150g/mol. What is the molecular formula of ribose? MOLECULAR FORMULA STEP1: Determine the molar mass of the empirical formula 12g/mol + 2 x 1.008g/mol + 16g/mol = 30g/mol STEP2: Divide the given molar mass by your answer from STEP1 150g/mol / 30g/mol = 5
  • 29. The empirical formula of ribose is CH2O. The molar mass of this compound was determined to be 150g/mol. What is the molecular formula of ribose? MOLECULAR FORMULA C1x5H2x5O1x5 = C5H10O5 STEP3: Multiply your empirical formula by your answer from STEP2
  • 31. MASS SPECTROMETER 1) Upload sample 2) Same is vapourized 3) Sample is ionized 4) Ions accelerated by electric field 5) Detection to mass-to-charge ratio based on details of motion 6) Ions assorted according to mass-to-charge ratio
  • 32. CARBON-HYDROGEN COMBUSTION ANALYZER 1)Weigh H2O absorber and CO2 absorber before experiment 2)Sample is burned 3)Absorbers are weighed again
  • 33. CARBON-HYDROGEN COMBUSTION ANALYZER A 1.000g sample of pure compound, containing only carbon and hydrogen, was combusted in a carbon-hydrogen combustion analyzer. The combustion produced 0.6919g of water and 3.338g of carbon dioxide. a)Calculate the masses of the hydrogen and the carbon b)Find the empirical formula of the compound.
  • 34. CARBON-HYDROGEN COMBUSTION ANALYZER A 1.000g sample…The combustion produced 0.6919g of water and 3.338g of carbon dioxide. a) Calculate the masses of the hydrogen and the carbon Mass of H = 2.02g/mol H2 x 0.6919g H2O 18.02g/mol H2O = 0.07756g H2 This gives you the percent composition of hydrogen in water Mass of C = 12.01g/mol C x 3.338g CO2 44.01g/mol CO2 = 0.9109g C .: there was 0.0775g of H and 0.911g of C always 0.112 always 0.27289
  • 35. CARBON-HYDROGEN COMBUSTION ANALYZER A 1.000g sample…The combustion produced 0.6919g of water and 3.338g of carbon dioxide. b) Find the empirical formula of the compound Moles of H = 0.07756g 1.008g/mol = 0.07694mol Moles of C = 0.9109g 12.01g/mol = 0.07584mol SMALLEST ANSWEREmpirical formula = C0.07694/0.07584H0.07584/0.07584 = C1.0H1.0 = CH .: the empirical formula is CH
  • 36. HYDRATED SALTS A 50.0g sample of Ba(OH)2·XH2O contains 27.2g of Ba(OH)2. a)Calculate the percent, by mass, of water in the sample b)Find the value of X
  • 37. HYDRATED SALTS A 50.0g sample of Ba(OH)2·XH2O contains 27.2g of Ba(OH)2. a) Calculate the percent, by mass, of water in the sample = (total mass of sample) – (mass of Ba(OH)2 in sample) x 100% (total mass of sample) = 50.0g – 27.2g x 100% 50.0g = 45.6% .: the percent by mass of water is 45.6%
  • 38. HYDRATED SALTS A 50.0g sample of Ba(OH)2·XH2O contains 27.2g of Ba(OH)2. b) Find the value of X nH2O = m/M = (50.0g – 27.2g) (18.02g/mol)  this is the molar mass of H2O = 1.27mol H2O 0.159/0.159 mol Ba(OH)2·1.27/0.159 mol H2O Ba(OH)2·8H2O nBa(OH)2 = m/M = (27.2g) (171.3g/mol) = 0.159 mol Ba(OH)2SMALLEST ANSWER .: X is 8