Colligative properties equations and formulas examples in. The colligativeproperty law can be expressed using the equation. Freezing point depression lab add 6g of distilled water into test tube and submerge thermometer into it before putting it into a deep freeze. Colligative properties determination of the molar mass of a compound by freezing point depression. Alternatively, a colligative property is a measure of the depression of the activity of the solvent in solution, compared to the pure state. Before you begin, save this lab report template on your computer as lastnameapchem4b. Health professions and related clinical sciences 51. Determine freezing point of each system examined from analysis of its cooling curve. Version 4201490001 lab report assistant this document is not meant to be a substitute for a formal laboratory report. If so, you have already been exposed to a group of four physical phenomena called colligative properties. Analysis the following are the calculations required for the analysis questions.
Colligative properties are also affected by temperature. Conclusion the purpose of this experiment was to determine. Colligative properties of solutions such as freezing point. D t km, where d t is the change in freezing or boiling point, k is a solventspecific constant, and m is the solutions molality. These properties include boiling point elevation, freezing point depression, and osmotic pressure. Colligative collective properties of solutions science. The vapor pressure is the escaping tendency of solvent molecules.
Examples include the pressure of an ideal gas and the depression of the freezing point. Such properties are called colligative properties of the solution. Overall, the colligative properties can be very useful in our everyday lives. It is designed to help students link chemical computations with authentic laboratory chemistry. The more, or less, of a solute that is present in ratio with the solvent will affect the calculations of the four colligative properties outlined above. There are four colligative properties, and you already. Calculation of the properties only works perfectly for ideal solutions. In this experiment we will use the colligative property of freezing point. A greener approach for measuring colligative properties. Datamate program, students will then select the region shown above as. The number ratio can be related to the various units for concentration of solutions, for example, molarity, molality, normality chemistry, etc. How does antifreeze lower the freezing point of water in the cooling systems of automobiles.
This laboratory experiment is appropriate for students enrolled in upper division atmospheric science. This activity is used in a general chemistry class consisting of juniors and seniors in high school and it is completed before any notes are given on the subject. I am doing the data analysis and writing a lab report on a colligative properties experiment involving freezing point depression. In the colligative properties chemistry laboratory kit, students measure boiling points to determine how the concentration of a solution changes due to osmosis. The neat thing about them is that it doesnt matter what the solute is, just how much is there. Colligative properties depend only on the number of dissolved particles that is, the concentration, not their identity. The vapor pressure of a pure liquid at a given temperature is a characteristic property of that liquid. Aug 25, 2019 this lab activity is used to introduce colligative properties in solutions, concentrating primarily on the effects of nonvolatile solutes on freezing point.
Colligative properties in real life chemical education. Some examples of colligative properties are vapor pressure, boiling point, freezing point, and osmotic pressure. Chemists exploit the phenomenon of freezingpoint depression in the analysis of solid organic compounds. Colligative properties are dependent on the ratio of solute and solvent particles in a. Colligative properties equations and formulas examples. The colligative property of freezing point depression was the theory at work behind what was observed in the experiment trials. A pure substance in liquid or solid form will have certain properties such as a certain melting or boiling point. This document is not meant to be a substitute for a formal laboratory report. As a first step towards the greening of instructional laboratories, we present a new greener version of a laboratory procedure designed to measure colligative properties. The purposes of this experiment were to observe and measure the effect of a solute on the freezing point of a solvent and to determine the molar mass of the unknown solute labeled eagles.
Freezingpoint depression, a colligative property, is investigated. The colligative property of freezing point depression was the theory at work behind. Mode of separation only difference to other hplc methods specialist detectors can be used to determine properties of the samples investigated special gpcsec software required to perform analysis. Like pure solids, liquids and gases, solutions have welldefined physical properties e. Determination of molar mass by freezing point depression using paradichlorobenzene introduction. The virtual lab is an online simulation of a chemistry lab. The lab report assistant is simply a summary of the experiment s questions, diagrams if needed, and data tables that should be addressed in a formal lab report. The lab allows students to select from hundreds of standard reagents aqueous and manipulate them in a manner resembling a real lab. Colligative properties of solutions presentation chemistry. Lab report 4 ch 204 introduction to chemical practice.
Solute is the lesser component and solvent the greater component in a solution. However, when a nonvolatile solute is dissolved in the liquid, the vapor pressure of the liquid is reduced. The physical properties of solutions that depend on the number of dissolved solute particles and not their specific type are known as colligative properties. Colligative properties are based on the amount of a substance not what it is. Colligative properties are those that depend on the concentration of particles in a solution, not upon the identity of those particles. An ebook reader can be a software application for use on a computer such as microsofts free reader application, or a booksized computer this is used solely as a reading device such as nuvomedias rocket ebook. Colligative propertiesstudent laboratory kit flinn scientific. Any questions on azeotropes, before we get to colligative properties. Oct 30, 2016 colligative collective properties of solutions they are properties whose values depend only on the number of solute particles per unit volume of solution and not on the type of solute, collective properties of solutions are vapour pressure depression, boiling point elevation and freezing point depression. Analysis 2000 software was utilized to aid in the determination. This lab activity is used to introduce colligative properties in solutions, concentrating primarily on the effects of nonvolatile solutes on freezing point.
Experiment 14 lab report chem molar mass of of a solid. Robin furslund october, 2016 introduction introduced in 1891 by wilhelm ostwald the word colligative classified solute properties into three categories one being colligative properties. Colligative properties of solutions ideally depend only on the number of solute particles per solvent molecule and not on the nature of the solute or solvent. Antifreeze is the realworld example of a colligative property. The colligative properties of solutions strand phases of matter and kinetic molecular theory topic investigating properties of matter primary sol ch. The number ratio can be related to the various units for concentration of solutions, for example, molarity, molality. The greener procedure substitutes the nontoxic, noncarcinogenic compounds stearic, myristic, lauric, and palmitic acids for the less benign aromatic compounds pdichlorobenzene, benzil, biphenyl, naphthalene, and nitrotoluene. Colligative properties postlab analysis the following are. Exploring freezing point depression using freeze pops. The three colligative properties are boiling point, freezing point, and vapor. What was the objective of this experiment and how was it achieved. The purpose of this experiment was to determine the molar mass of an unknown, nonvolatile solute. Colligative properties of solutions properties depending on number of particles ions, molecules dissolved. Colligative properties of solutions depend on the quantity of solute dissolved in the solvent rather than the identity of the solute.
Dissociationwhen neutral combinations of particles separate into ions while in aqueous solutionup to this point you have only thought about solution as a particle dissolved in water. We had to calculate the molar mass of an unknown fatty acid that had been added to stearic acid. To answer this, we need to understand the concept of colligative properties. Heres all the info for the lab writeup we have to do in class. Colligative properties depend on the lowering of the escaping tendency of solvent particles by the addition of solute particles.
Experiment on colligative properties colligative properties are the properties of solutions that depend on the total concentration of solute particles in solution. Dt kmolality use these to determine molar masses of solutes. Colligative property, in chemistry, any property of a substance that depends on, or varies according to, the number of particles molecules or atoms present but does not depend on the nature of the particles. Determination of the molar mass of a compound by freezing point depression. An ebook reader can be a software application for use on a computer such as microsofts free reader. Chem 1252 lab report 3 lab partner n\a colligative. If the number of particles is significant, colligative. Colligative properties freezingpoint depression and boilingpoint elevation computer simulation colligative properties of solutions. Still i have found colligative properties to be of great interest and still approach the topic qualitatively with my chemistry 2 and honors chemistry 2 students. The theory and experiment showed conclusively that polymer solutions do.
Jul 29, 2016 colligative properties by definition are cases where the concentration of a solute not necessarily what the solute is is related to the effect. There are many materialssolutions that adding more of something will always result in some consisten. To complete this calculation, the mass of solute and solvent must be known as well as the freezing pointsboiling points of the pure solvent and the solution. Dissolved solute in pure liquid will change the physical property of the liquid, i. List three colligative properties and suggest a rationale for the choice of the word colligative to describe these properties. The four colligative properties that change as a result of the addition of solute are freezing point, boiling point, vapor pressure, and.
Technology is used to collect, graph and analyze both the cooling of a pure solvent and the cooling of the. In this experiment, the lauric acidbenzoic acid solution will exhibit a more. Since colligative properties do not depend on the nature of the solute, they may be used to determine the molecular weight of a substance. Learn vocabulary, terms, and more with flashcards, games, and other study tools. The colligative properties include vapor pressure lowering, boiling point elevation, freezing point depression, and osmotic pressure.
Colligative properties by definition a colligative property is a solution property a property of mixtures for which it is the amount of solute dissolved in the solvent matters but the kind of solute does not matter. One of these properties that we have many uses for is a property known as colligative properties. The phenomenon of freezing point lowering will be examined. Colligative properties reflect the chemical potential of the solvent in solution.
Lab 2 ice cream chemistry there are many chemical properties that have been utilized by humans in order to suit our own needs. The boiling points of solutions are always higher, and the freezing points of solutions are always lower, than those of the pure solvent. Colligative properties include vapor pressure lowering, boiling point elevation, freezing point depression, and membrane. The purpose of this experiment was to analyze the colligative properties, ones whose values depend only on the number of solute particles present, not on their chemical identity, of different solutions. In the late nineteenth century the french chemist francois raoult noted that the vapor pressure of a pure. Colligative properties depend on the number of particles present in a solution, but not on the identity of the particles. Colligative properties are dependent only on the number of particles in a solution, and not their identity. Colligative properties are properties of solutions that depend on the number of particles in a volume of solvent the concentration and not on the mass or identity of the solute particles. To complete this calculation, the mass of solute and solvent must be known as well as the freezing pointsboiling points of.
Colligative properties such as freezing point depression or boiling point elevation can be used to calculate the molecular weight of a soluble solid. When a solute dissolves in a solvent such as water, various physical properties are affected. The lab activity includes background information on colligative properties and how. I dont really understand how to do the analysis part, so any help would be really appreciated. To perform a second trial during the colligative properties lab, you can just remelt your first solution to obtain a second measurement. So youve got to know, which things form azeotropes. I calculated the molar mass of my groups unknown sample to be 211. Colligative properties lab with an unusual problem. Freezingpoint depression and boilingpoint elevation. So it implies that there is a collective effort to change properties of a pure liquid or solid. Colligative properties of solutions depend on the concentration of solute particles but not on their identity. Molality is defined as moles of solutekg of solvent. Since colligative properties do not depend on the nature of the solute, they may be used to determine the molecular weight of a.
Freezing point depression is one of the colligative properties of solutions discussed in this unit. Colligative properties lab freezing point depression. Freezingpoint depression to determine an unknown compound. The cooling curves for the solutions were generally accurate, and resulted in a realistic molar mass, which means this lab was a success. Colligative properties freezing point depression lab format. These characteristics are fully dependent on the number of particles dissolved in the solution it does not matter what those particles are. Colligative properties include vapor pressure lowering, boiling point elevation. There is a direct relationship between the boiling point elevation and the number of particles present in a solution. For example, if you added the same number of moles of sugar and salt, the salt would have a greater effect than the sugar because it is ionic. After finding many articles on antifreeze, i decided to research more into the subject. The lab report assistant is simply a summary of the experiment s questions, diagrams if needed, and data tables that should be addressed in a formal. When a solute is added to water the physical properties of freezing point and boiling point change.
Colligative properties include changes in vapor pressure. Experiment 14 lab report chem molar mass of of a solid studocu. Experiment on colligative properties boston university. The four colligative properties that change as a result of the addition of solute are freezing point, boiling point, vapor pressure, and osmotic pressure. Colligative property an overview sciencedirect topics. At least, everyday life during the wintertime or when boiling water and making pasta. At this temperature, the gaseous and liquid states of. Colligative properties are properties of a solvent, such as freezing point depression and boiling point elevation, which depend on the concentration of solute particles dissolved in the solvent. Historically, colligative properties have been one means. Raoults law is concerned with the vapour pressure depression of solutions.
A change in a property of a solvent that depends on the concentration of dissolved solutes particles is called a colligative property. In chemistry, colligative properties are those properties of solutions that depend on the ratio of the number of solute particles to the number of solvent molecules in a solution, and not on the nature of the chemical species present. View notes colligative properties postlab from chemistry laboratory at high technology high sch. The properties that exhibit such changes are called the colligative properties and include. Investigating freezing point depression and cirrus cloud. I scream, we all scream for colligative properties. Jul 03, 2009 a presentation discussing the main colligative properties of solutions, applicable for high school chemistry or ap chemistry slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. In chemistry, colligative properties are properties of solutions that depend on the ratio of the number of solute particles to the number of solvent molecules in a solution, and not on the nature of the chemical species present. So properties of solutions are going to be different from the properties of the actual solvent by itself.
Lets talk about colligative properties solutions and colligative properties are a collection of physical properties of the solution that are affected by the number of solute particles. Colligative properties include changes in vapor pressure, boiling point, freezing point, and osmotic pressure. The greener procedure substitutes the nontoxic, noncarcinogenic compounds stearic, myristic, lauric, and palmitic acids for the less benign aromatic compounds p. Some properties of the solvent are changed only by the number of solute particles present, without regard to the particular nature of the solute. Colligative properties are all dependent upon the molality m of a solution. The objective of this experiment is to determine the molar mass of an unknown solute by measuring the freezing point depression of a solution of this solute in a solvent as compared to the freezing point of the pure solvent. Colligative properties of solutions vernier vernier software. Apr 14, 2009 heres all the info for the lab writeup we have to do in class. When the vapor pressure of a solvent is equal to atmospheric pressure, the solvent boils. Colligative properties of solutions chemistry tutorial.
360 1213 1261 785 1120 241 813 772 6 1359 1068 889 776 992 772 1555 130 628 1388 1526 1056 302 1505 437 1229 1109 1186 1440 813 50 689 346 1009