CHEMICAL LABORATORY REPORTCOLLIGATIVE SOLUTIONS

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NAME : RAFIKA KAMAL

CLASS : XII IPA C

NIS: 9963055803

SMAN 01 UNGGULAN KAMANRE

2013/2014

FOREWORD

Worship and praise the presence of God Almighty who has bestowed His grace and guidance , so that I can finish the report entitled " Colligative properties Electrolytes and Non- Electrolyte Solution " in the allotted time .      This report was prepared to fulfill the task of Practical Chemistry . This report will not be completed without the help of various parties either directly or indirectlyThe author realizes that the writing of this paper is far from perfect . To that end , criticism and constructive suggestions in this paper greatly improved the authors expect .Authors hope this paper can provide benefits to the reader , especially to determine the colligative properties of electrolyte and non- electrolyte solution .

author

TABLE OF CONTENTSCHAPTER 1

1.1 BACKGROUND……………………………………………….

1.1.1 ∆ P…………………………………………………………

1.1.2 ∆Tb………………………………………………………..

1.1.3 ∆Tf………………………………………………………...

1.1.4 π……………………………………………………………

CHAPTER 2

2.1 METODE…………………………………………………………

2.1.1 ∆ P…………………………………………………………

2.1.2 ∆Tb………………………………………………………..

2.1.3 ∆Tf………………………………………………………...

2.1.4 π……………………………………………………………

CHAPTER 3

3.1 CONCLUSION……………………………………………………

3.2 FEEDBACK…………………………………………………………….

3.3 ADVICE……………………………………………………………

3.4 REFERENCES……………………………………………..

CHAPTER 4

4.1 APPENDIX

4.1.1 ∆ P…………………………………………………………

4.1.2 ∆Tb………………………………………………………...

4.1.3 ∆Tf………………………………………………………...

4.1.4 π……………………………………………………………

CHAPTER I

COLLIGATIVE ELECTROLYTE SOLUTION AND NON ELECTROLYTIC

1.1 BACKGROUND OF PROBLEM

Colligative properties are properties that the solution does not depend on the kinds of solutes but solely determined by the amount of solute ( solute concentration ) . Roult law is the basis of colligative properties of solutions . These four properties that are :

1. Decrease in vapor pressure relative to the vapor pressure of the pure solvent .

2. Increased boiling point3. Decrease freezing4. Symptoms of osmotic pressure .

Colligative properties distinguishable to be two kinds , namely the nature of the Non-electrolytes and electrolyte solution . That is because the solute in the electrolyte solution to increase in numbers due to break down into ions , while the solute in solution nonelectrolyte still accounted for not break down into ions , in accordance with these things , the colligative properties of nonelectrolyte solution is lower than the colligative properties of solutions electrolyte . A solution is a homogeneous mixture and can be either solids or liquids . However, the most common solution is an aqueous solution , in which a particular substance is dissolved in a suitable solvent liquid tangible until a certain concentration .

1.1.1 Vapor Pressure Drops

Evaporation process is a form of a substance changes from a liquid to a gas . There is a tendency that a liquid substance will undergo evaporation . The rate of evaporation of any liquid substance is not the same , but in general will be more volatile liquids if the temperature is higher

Vapor pressure drop is the tendency of molecules to escape from the liquid molecules in the surrounding fluid and becomes steam . If the fluid is inserted into a solute that is difficult to evaporate and form a solution , then only partially evaporating the solvent alone , karene others evaporation was prevented by the solute . The magnitude of this decline investigated by Raoult then be formulated as follows .Many say the least vapor above the liquid surface was measured by vapor pressure of the liquid. The higher the temperature the more fluid vapor above the liquid surface and means higher vapor pressure . The amount of vapor above the surface will reach a saturation at a certain pressure , because when the pressure of saturated vapor condensation will occur , the vapor pressure is called the saturated vapor pressureAt the time konvalatil substance added to a solution , there will be a decrease in vapor pressure . At a temperature of 20 C saturated water vapor pressure above the water surface was 17.53 mmHg . The amount of water vapor pressure reduction due to solutes called vapor pressure drop solution .Since the year 1887 - 1888 Francois Mario Roult has studied the relationship between vapor pressure and solute concentration , and get a conclusion that the magnitude of the vapor pressure of a solution is proportional to the mole fraction of the solvent and vapor pressure of the pure solvent . Vapor pressure reduction by law Roult , the vapor pressure of a liquid in the space above the ideal solution depends on the liquid mole fraction in solution PA = XA . PAO . Of law Roult turns pure solvent vapor pressure greater than the vapor pressure of the solvent in the solution . So the solvent vapor pressure drop is directly proportional to the mole fraction of the solute .

P = Po . XpelarutP = vapor pressure of the solutionX = mole fractionP = vapor pressure of the pure solventThe decrease in the vapor pressure of the solution caused by the solute . To determine how much influence the number of solute particles to decrease the vapor pressure can be written :           P = Po - P

Because X1 = 1 - X2 to a solution consisting of two components , the Roult law can be written :

P = X solvent solution . P solvent

Thus , changes in solvent vapor pressure is directly proportional to the mole fraction of the solute . The negative sign implies a decrease in vapor pressure . Always lower vapor pressure above the aqueous solution than the pure solvent above .1.1.2 Enhanced Boiling Point

The next trait is the boiling point elevation and freezing point depression . The boiling point of the solution is always higher than the boiling point of the solvent . the opposite is true at the freezing point of the solution is lower than the solvent . This trait is formulated as follows :When the liquid temperature is raised , the more liquid is evaporated. At a certain temperature the amount of vapor above the surface of the liquid will cause the vapor pressure is equal to the outside air pressure . The current state of the vapor pressure of the liquid on the surface of the liquid is equal to the pressure of the surrounding air is called boiling and temperature when the vapor pressure above the liquid surface is equal to the vapor pressure of the outside is called the boiling point . At the time konvalatil substances added to the solution will increase the boiling point of the solution.The boiling point of pure water at a pressure of 1 atm is 100 C. This means the vapor pressure of pure water will reach 1 atm ( equal to the outside air pressure ) when the water is heated to 100 C. Thus, when the outside air pressure is less than 1 atm ( eg top of the mountain ) , the boiling point of water is less than 100 C.When dissolved into pure water of a substance that is difficult to evaporate , then at a temperature of 100 ° C the vapor pressure of water has not reached 1 atm and mean water was not boiling . To be able to boil ( water vapor pressure reaches 1 atm ) will require higher temperatures . The magnitude of the temperature rise that is called the boiling point elevation .According to the law Roult , the magnitude of the increase in boiling point solvent is proportional to the product of solution molality ( m ) and the boiling point elevation molalnya ( Kb ) . Can be formulated as :                                                    Tb = Kb . mΔifM = n x 1000                             PSo the above formula can be expressed as follows :

Tb = Kb ( n x 1000)                      p

  Tb = great depression of freezing point  Kb = constant boiling point rise  m = molality of solute   n = number of moles of solute   p = mass of solvent

Kb price varies for each solvent . Kb is obtained by measuring the increase in boiling point of the aqueous solution molalitasnya known (ie , containing a known amount of solute and mass molalnya ) . The boiling point of the solution is the boiling point of the pure solvent coupled with the increase in boiling point or Tb = Tb + Tb ( Oxtoby , 2001) .

1.1.3Penurunan point Frozen

The process of freezing a liquid occurs when the temperature is lowered so that the distance between the particles in such close proximity to each other and finally worked attractive forces between molecules are very strong . The presence of particles of solute will result in the movement of solvent molecules blocked , consequently to close the distance between the molecules required lower temperature . The difference in temperature presence of solute particles called freezing point depression . At the time konvalatil substances added to the solution will decrease the freezing point of the solution .As well as the boiling point elevation , freezing point depression is proportional to the product solution molality solution with solvent freezing point depression constant ( Kf ) is expressed by the equation : Tf = Kf . mΔ

Tf = Kf ( n x 1000)         p Tf = freezing point depression Kf = constant molal freezing ttitik  n = number of moles of solute  p = mass of solventThe freezing point of the solution is the freezing point of the pure solvent is reduced with a decrease in freezing point . Measurement of freezing point depression , as well as an increase in boiling point , can be used to determine the molar mass of an unknown substance .

Symptoms of freezing point depression analogous to increase the boiling point . Here we take into consideration only the case if the first solids were crystallized from solution is a pure solvent . If the solute crystallizes together solvent , then things get more complicated . Pure solid solvent is in equilibrium with a certain pressure of the solvent vapor , sebagimana determined by temperature . The solvent in the solution as well , is in equilibrium with a certain pressure of the solvent vapor . If the solid solvent and solvent in the solution to be together , they must have the same vapor pressure . This means that the freezing temperature of the solution can be identified as a temperature when the vapor pressure curve intersects with the pure solid solvent solution curve . If the solute is added to a solution , the solvent vapor pressure down and freezing , the temperature when the first crystals of pure solvent began to emerge , down . Thus the difference is negative and the freezing point depression can be observed.

1.1.4 Osmotic Pressure

Four colligative properties especially important in cell biology , because an important role in trasfor molecules through the cell membrane . This is called a semipermeable membrane , which allow small molecules through but hold large molecules such as proteins and carbohydrates . Semi- permeable membrane to separate the small solvent molecules of solute molecules are large . Events movement of particles ( molecules or ions ) through a semi-permeable wall is called osmotic . Pressure which will result from the osmotic pressure is called osmotic pressure . Large osmotic pressure was measured by means of osmometer , the burden on the surface of the solution into a parallel rise in the previous surface .Osmosis or osmotic pressure is the process of transfer of liquid from hipotonis solution to hypertonic solution through a semipermeable membrane . Osmosis can be stopped if given pressure , the pressure exerted is called osmotic pressure . Osmotic pressure formulated :Based on the ideal gas equation :

PV = nRTthen the pressure

P = Nrt VIf the osmotic pressure of the solution is denoted by , the above equation πcan be obtained :

= nRTπ

or                                                                 = M R Tπ

For the electrolyte solution was found irregularities by Vanit Hoff . These deviations occur because the electrolyte solution in water dissociates into ions , so that the amount of solute to be redoubled . From here it takes multiplier or commonplace called Vanit Hoff factor . Formulated as follows :

= osmotic pressureπM = molar concentrationR = ideal gas constant ( 0.082 L atm K mol )T = absolute temperature ( K )

Particles in a non- electrolyte solution is not the same as the number of particles in the electrolyte solution , although the concentration of both . This is because the electrolyte solution decomposes into ions , whereas the non- electrolyte solution does not break down into ions . Thus the solution colligative properties distinguished on colligative properties of non electrolyte solution and colligative properties of electrolyte sol.

CHAPTER II

METHODS

1.2.1 Vapor pressure drop ( P )Δ

EQUIPMENT AND MATERIALS : water sugar salt Pan 2 pieces stove Thermometer

HOW TO WORK : Add salt to the pan first and sugar in a second pot . enter into a pot of water with the same volume . Turn on the stove Put the pan on the stove Observe every hour .

NO SOLUTIONS TEMPERATURE FACTS1 Water ( H2O )

2 water + salt ( NaCl )

3 Air + sugar ( C6H12O6 )

 OBSERVATION RESULTS :

2.1.2 Increase Boiling Point ( Tb )Δ

EQUIPMENT AND MATERIALS : water instant noodles salt Pan 2 pieces stove Thermometer

HOW TO WORK : Add salt to the pan first and second instant noodles in the pan . enter into a pot of water with the same volume . Turn on the stove Put the pan on the stove Observe every hour .No

solution temperature facts

1 water ( H2O )2 water + salt ( NaCl )3 Air + instant

noodles

Observation results :

2.1.3 . Decrease Freezing Point ( Tf )Δ

EQUIPMENT AND MATERIALS : water milk salt 2 cups clam freezer Thermometer

HOW TO WORK : Add salt and milk on the first glass on the second glass . enter into a beaker of water with the same volume . Enter the second glass into the freezer Observe every hour .

NO SOLUTION TEMPERATURE FACTS

1 WATER ( H2O )

2 water + salt ( NaCl )

3 water+ milk (C6H12O6)

Observation results :

2.1.4 Osmotic pressure ( )π

TOOLS AND MATERIALS

Baby diapers with different brands water needle

HOW TO WORK

Open each diaper Drill diaper with needle Sirami each diaper with water Examine each diaper Posts observations in the table :No Brand diapers description1 sweety Less absorbency, easy to leak2 Mamy poko Strong absorption, not easy to

leak

CHAPTER 3

3.1 ConclusionFreezing point depression and boiling point is affected by the concentration and type of substance .If the same type of solution , different konstrasi the amount of freezing point depression and boiling point rise .Colligative properties of electrolyte solution has greater than the colligative properties of non- electrolyteThe higher the concentration , the lower the freezing point .The lower the concentration , the greater the distance between the ions and ions increases.Factors affecting the increase in boiling point is concentration and price kb .Increasingly tinggin concentration , the increase in the higher boiling point solvent .The higher the price kb , rise higher boiling point solventThe boiling point elevation is not influenced by the type of substance that is dissolved .The bigger the solution , the higher the freezing point depression of the solution.Decrease freezing point of solution ( Tf ) is proportional to the solution .ΔThe freezing point of the pure solvent is higher than the freezing point of the solution .The freezing point of the electrolyte solution is lower than nonelectrolyte solution at the same kemolalan .The concentration similar to the electrolyte solution contains more than the number of particles nonelectrolyte solution .Boiling point is the temperature when the saturated vapor pressure of a liquid is equal to the outside air pressure .The increase in boiling point is the difference in boiling point solvent boiling point solvent

3.2 Suggestions

For further practican to pay attention to the thermometer carefully so it does not occur at a temperature measurement error

Bibliography

www.getupbangkit.blogspot.nl/2010/09/laporan-kimia-titik-beku-oleh-bangkit.html?m=1www.mahpudeen.blogspot.com/2013/09/laporan-kimia-penurunan-tekanan-uap.html?m=1www.sumiyatianis.bolgspot.nl/2013/09/laporan-hasil-praktikum-kenaikan-titik.html?m=1Achmad, Hiskia.2001. Kimia larutan. Cetakan kedua. Bandung: Citra Aditya Bakti.

Arsyad, M. Natsir. 2010. Kamus kimia arti dan penjelasan istilah. Jakarta: Penerbit Gramedia Pustaka Utama.

APPENDIX