Chapter 2.1 Solutions and Their Properties

1.Types of Solution
2. Energy of Solution
3, Concentration of Solution

1. GENERAL CHEMISTRY II
WEEK 3-4

2. 1.Usedifferentwaysofexpressing
concentrationofsolutions:percentbymass,
molefraction,molarity,molality,percentby
volume,percentbymass,ppm.
2.Performstoichiometriccalculationsfor
reactionsinsolution.
3.Describetheeffectofconcentrationonthe
colligativepropertiesofsolutions.

3. 4.Differentiatecolligativepropertiesof
nonelectrolytesolutionsandofelectrolyte
solution.
5.Calculatetheboilingpointelevationand
freezingpointdepressionfromthe
concentrationofasoluteinasolution

4. 6.Calculatemolarmassfromcolligative
propertydata.
7.Describelaboratoryproceduresin
determiningconcentrationofsolution.

5. General Chemistry 2 –Senior High School (STEM)
EQ: What types of solutions are encountered
everyday?

6. Identifythesoluteandsolventineachofthe
followingsolutions,explainyouranswers.
1.25gramsofsaltdissolvedin95mLofwater.

7. 2.25mLofwatermixedwith75mLofisopropyl
alcohol.

8. 2.Tinctureofiodinepreparedwith0.20gramof
iodineand20.0mlofethanol

9. Solutionsaremixturesoftwoormore
substancesdistributedthroughoutasingle
phase.
Atoms,ions,ormoleculesarethoroughly
mixedinasolutionsuchthateachpartofthe
mixturehasuniformcompositionand
properties.

10. Asolutionconsistsofasoluteandasolvent.
TheSoluteisthesubstancedissolvedina
solutionandisusuallypresentinsmaller
amount;solventisthedissolvingmedium.

11. SOLUTE SOLVENT SOLUTION EXAMPLE
GAS GAS GAS Oxygen in
Nitrogen
GAS LIQUID LIQUID Carbon Dioxide
in water
GAS SOLID SOLID Hydrogen in
Palladium
LIQUID LIQUID LIQUID Ethanol in
water
LIQUID SOLID SOLID Mercury in
silver
SOLID LIQUID LIQUID Salt in water
SOLID SOLID SOLID Copper in tin
(bronze)

12. Asolutioncanbeclassifiedasunsaturated,
saturated,orsupersaturateddependingon
thequantityofsolutepresentinit.

13. UnsaturatedSolutioncontainslesssolute
thansolvent’scapacitytodissolve.This
meansthatthesolventcanstilldissolvemore
solute.
SaturatedSolutioncontainsthemaximum
amountofsolutethatthesolventcan
dissolveatacertaintemperature.

14. Supersaturatedsolutioncontainsmore
dissolvedsolutethanispresentinasaturated
solution.Thistypeofsolutionisunstablesuch
thattheexcesssolutecancrystallizeinthe
solutionbyaddinga“seedcrystal”(aprocess
calledseeding)orbyscratchingthesidesof
thecontainer.

15. General Chemistry 2
EQ: How do liquid solution forms?

16. Fortwosubstancestoformasolution,they
musthavethesamenatureintermsof
Polarity.
Theformationofliquidsolutiontakesplacein
threesteps:
1.Overcomingtheintermolecularforcesinthe
solventtogiveroomforthesolute.

17. 2.Separatingthesoluteintoitsindividual
components.
3.Allowingthesoluteandsolventtointeract
toformthesolution.

18. Itistheenthalpychangeassociatedwiththe
formationofthesolution.
Itisequaltothesumofthe Hvaluesfor
thethreesteps.
Apositiveenthalpyofsolutionsignifiesan
endothermicprocess,whilenegativeindicates
anexothermicprocess.

19. Theprocessisexothermic,ifmoreenergyis
releasedwhennewbondsformthanisused
whenbondsarebroken.
Theprocessisendothermic,ifmoreenergyis
required(used)whenbondsarebrokenthan
isreleasedwhennewbondsareformed.

20. General Chemistry 2
EQ: Why should solutions be expressed in a
correct concentration units?

21. Itisameasureoftheamountofsoluteina
givenamountofsolventorsolution.
Onetypeofsolutionmaybepreparedand
expressedindifferentconcentrations.
Example:
Acupofhotwaterwithoneteaspoonof
coffeeisanaltogetherdifferentsolutionthan
acupofwaterwithafewteaspoonofcoffee.

22. Example:
Medicationsarealsosolutionsofsubstances,
A5mLdoseofacertainconcentrationof
medicinemightcureasickperson,buta5mL
doseofahigherconcentrationmightalready
harmfultotheperson.

23. 1.PercentbyMass
2.PercentbyVolume
3.PercentbyMass-Volume
4.MoleFraction
5.Molality
6.Molarity
7.PartsperMillion

25. 1.Asalinesolutionwithamassof355ghas
36.5gofNaCldissolvedinit.Whatisthe
masspercentconcentrationofthe
solution?

26. Given:
MassofSolute=36.5grams
MassofSolution=355grams
Formula:Percentbymass=
�??????����������
�??????���������??????��
x100
Percentbymass=
36.5��??????��
355��??????��
x100
Percentbymass=10.28%

27. 2.Awinecontains12%alcoholbyvolume.
Calculatethevolume(inmL)ofalcoholin
350mLofthewine.

28. Given:
PercentbyVolume=12%
VolumeofSolution=350mL
Volumeofsolute=x
Formula:%byvolume=
��������������
�������������??????��
x100
12%=
??????
35��??????
x100
12
100
(350mL)=x
42mL=x

29. Percent by Mass –Volume = mass of solute in grams
volume of solution in mL
1.Whatistheconcentrationinpercentby
mass/volumeof150mLofsolution
containing30gofsolute?
X 100

30. Given:
volume of solution (mL) : 150 ml
mass of solute (g) : 30 grams
Find:
% by mass-volume
Formula:
% by mass-volume=
�??????����������??????��
�������������??????��??????��??????
x 100

31. % by mass-volume =
30��??????��
150�??????
x 100
= (0.20) x 100
= 20 %

32. A50mLof12%bymass-volumesolutionwas
usedinanexperiment.Howmanygramsof
solutedoesthesolutioncontain?

33. A50mLof12%bymass-volumesolutionwas
usedinanexperiment.Howmanygramsof
solutedoesthesolutioncontain?
Given:
volumeofsolutioninmL=50mL
%bymass-volume=12%
Find:
Massofsoluteingrams=?

34. Formula:
% by mass-volume=
�??????����������??????��
�������������??????��??????��??????
x 100
12 % =
??????
50��
x 100
12
100
(50ml) = x
6 g = x

35. Themolefraction(x)ofacomponentina
solutionisequaltothenumberofmolesof
thecomponentdividedbythetotalnumber
ofmolesofallthecomponentspresent.
Thesumofallofthemolefractionsofall
componentsinallsolutionwillalwaysbe
equaltoone.

37. 1.25gofNaFismixedwith200gofH2O.
WhatisthemolefractionofNaFinthe
solution?
Step1:
Given:
solute:______________
solvent:______________
Find:_______________

38. 1.25gofNaFismixedwith200gofH2O.
WhatisthemolefractionofNaFinthe
solution?
Step1:
Given:
solute:25gofNaF
solvent:200gofH2O
Find:molefractionofNaF

40. Formula:
Step 2: Convert the given mass of solute and
solvent into moles using molar mass.
Given:_____________________

41. Mass to mole
-solute: 25 g of NaF
Molar Mass
Na : 1 x 23 = 23 g/mole
F : 1 x 19 = 19 g/mole
Total Molar Mass: 42 g/mole

42. Mass to mole
25 g of NaFX
1����
42�
= 0.60 moles of NaF
Moles of solute: 0.60 mole of NaF

43. Mass to mole
-solvent: 200 g of H2O
Molar Mass
H: 2 x 1 = 2 g/mole
O : 1 x 16 = 16 g/mole
Total Molar Mass: 18 g/mole

44. Mass to mole
200 g of H2O X
1����
18�
= 11.11 moles of H2O
moles of solvent: 11.11 moles of H2O

45. moles of solute + moles of solvent
=
Total Moles of Solution

46. Molesofsolute=0.60molesofNaF
Molesofsolvent=11.11molesofH2O
Total Moles of Solution = 11.71 moles

47. Molesofsolute=0.60molesofNaF
TotalMolesofSolution=11.71moles
X
solute=
0.60��������????????????
11.71�����
X
solute=0.05(FinalAnswer)

48. Molesofsolvent=11.11molesofH2O
TotalMolesofSolution=11.71moles
X
solvent=
11.11�����
11.71�����
X
solvent=0.95

49. X
solute= 0.05
X
solvent= 0.95
Total = 1

50. Calculatethemolefractionofeachcomponent
ofasolutioncontaining65gofethanol(C
2H
6O)
in350gofwater?

51. The molalityof a solution is the number of
moles of solute per kilogram of solvent.

52. Calculatethemolalityofasolution
containing16.5gofdissolvednaphthalene
(C
10H
8)in0.0543Kgbenzene(C
6H
6).
STEP1
Given:
Solute:_______________
Solvent:______________
Find:_____________

53. Calculatethemolalityofasolution
containing16.5gofdissolvednaphthalene
(C
10H
8)in0.0543Kgbenzene(C
6H
6).
Given:
Solute:16.5gC
10H
8
Solvent:54.3gC
6H
6
Find:molality

55. STEP 2: Convert the mass of solute into moles
using its molar mass.
Solute: 16.5 g C
10H
8
C : 10 x 12 = 120 g/mole
H : 8 x 1 = 8 g/mole
Total Molar Mass = 128 g/mole

56. STEP 2: Convert the mass of solute into moles
using its molar mass.
16.5 g C
10H
8 x
��??????�??????
��????????????
= 0.132 moles of C
10H
8

57. STEP 3: Calculate the Molality using the
formula.
m =
�.����??????�??????�
0.0543Kg
m = 2.49 moles/Kg

58. 10gofNaOHisdissolvedin500gwater.What
isthemolalityofsolution?

59. Molarityofsolutionisthenumberofmolesof
soluteperliterofsolution.Itisespecially
usefulindoingstoichiometriccalculations
involvingsolution.

60. Determinethemolarityofasolution
containing2.40gofsodiumchloride(NaCl)in
40.0mLofsolution.

61. Determinethemolarityofasolution
containing2.40gofsodiumchloride(NaCl)in
40.0mLofsolution.
STEP1
Given
Solute:__________________
Solution:_________________
Find:Molarity

62. Determinethemolarityofasolution
containing2.40gofsodiumchloride(NaCl)in
40.0mLofsolution.
STEP1
Given
Solute:2.40gofNaCl
Solution:40mL------0.04L
Find:Molarity

63. STEP2:Convertthegivenmassofsoluteinto
molesusingmolarmass.
Solute:2.40gofNaCl
Na:1x23=23g/mole
Cl:1x35=35g/mole
TotalMolarMassofsolute:58g/mole

64. STEP2:Convertthegivenmassofsoluteinto
molesusingmolarmass.
2.40 g of NaClx
1����
58��??????��
=0.04 moles

65. STEP 3: Calculate the molarity using the formula.
M =
�.���??????�??????�
�.��??????
M = 1 mole/L

66. Determinethemolarconcentrationsofa
solutionthatcontains25gofpotassium
hydroxide(KOH)in250mLofsolution.

67. What is the molarity of 0.25 molof NaClin
300 mL of solution?

68. Partspermillion(ppm)expressesthenumber
ofpartsofsoluteperonemillion/billionparts
ofsolution.

69. 1.25gramsofsodiumchlorideisdissolvedin
100gramsofwater,Whatisthe
concentrationofthesodiuminpartsper
million(ppm)?
STEP1
Given Find:ppm
Solute:_______________
Solvent:_______________
Solution:______________

70. 1.25gramsofsodiumchlorideisdissolvedin
100gramsofwater,Whatisthe
concentrationofthesodiuminpartsper
million(ppm)?
STEP1
Given Find:ppm
Solute:25gramsNaCl
Solvent:100gramswater
Solution:125grams

71. STEP2:Calculatetheppmusingtheformula.
ppm =
��??????�??????��
���??????�??????��
??????��
�
ppm = 200,000