General Chemistry 2 11 General Chemistry 2 – Grade 11 Quarter 3 – Module 11: Effect of Concentration on Colligative Properties of Solutions First Edition, 2020 Republic Act 8293, section 176 states that: No copyright shall subsist in any work of the Government of the Philippines. However, prior approval of the government agency or office wherein the work is created shall be necessary for exploitation of such work for profit. Such agency or office may, among other things, impose as a condition the payment of royalties. Borrowed materials (i.e., songs, stories, poems, pictures, photos, brand names, trademarks, etc.) included in this module are owned by their respective copyright holders. Every effort has been exerted to locate and seek permission to use these materials from their respective copyright owners. The publisher and authors do not represent nor claim ownership over them. Published by the Department of Education Division of Pasig City Development Team of the Self-Learning Module Writer: Eileen L. Del Rosario Editors: Ma. Victoria G. Seῇase Reviewer: Liza A. Alvarez Illustrator: Layout Artist: Management Team: Ma. Evalou Concepcion A. Agustin OIC-Schools Division Superintendent Carolina T. Rivera CESE OIC-Assistant Schools Division Superintendent Manuel A. Laguerta EdD Chief, Curriculum Implementation Division Education Program Supervisors Librada L. Agon EdD (EPP/TLE/TVL/TVE) Liza A. Alvarez (Science/STEM/SSP) Bernard R. Balitao (AP/HUMSS) Joselito E. Calios (English/SPFL/GAS) Norlyn D. Conde EdD (MAPEH/SPA/SPS/HOPE/A&D/Sports) Wilma Q. Del Rosario (LRMS/ADM) Ma. Teresita E. Herrera EdD (Filipino/GAS/Piling Larang) Perlita M. Ignacio PhD (EsP) Dulce O. Santos PhD (Kindergarten/MTB-MLE) Teresita P. Tagulao EdD (Mathematics/ABM) Printed in the Philippines by Department of Education – Schools Division of Pasig City General Chemistry 2 11 Quarter 3 Self-Learning Module 11 Effect of Concentration on Colligative Properties of Solutions Introductory Message For the facilitator: Welcome to the General Chemistry 2 Self-Learning Module 11 Effect of Concentration on the Colligative Properties Solutions This Self-Learning Module was collaboratively designed, developed and reviewed by educators from the Schools Division Office of Pasig City headed by its Officer-in-Charge Schools Division Superintendent, Ma. Evalou Concepcion A. Agustin, in partnership with the City Government of Pasig through its mayor, Honorable Victor Ma. Regis N. Sotto. The writers utilized the standards set by the K to 12 Curriculum using the Most Essential Learning Competencies (MELC) in developing this instructional resource. This learning material hopes to engage the learners in guided and independent learning activities at their own pace and time. Further, this also aims to help learners acquire the needed 21st century skills especially the 5 Cs, namely: Communication, Collaboration, Creativity, Critical Thinking, and Character while taking into consideration their needs and circumstances. In addition to the material in the main text, you will also see this box in the body of the module: Notes to the Teacher This contains helpful tips or strategies that will help you in guiding the learners. As a facilitator you are expected to orient the learners on how to use this module. You also need to keep track of the learners' progress while allowing them to manage their own learning. Moreover, you are expected to encourage and assist the learners as they do the tasks included in the module. For the Learner: Welcome to the General Chemistry 2 Self-Learning Module 11 Effect of Concentration on Colligative Properties of Solutions This module was designed to provide you with fun and meaningful opportunities for guided and independent learning at your own pace and time. You will be enabled to process the contents of the learning material while being an active learner. This module has the following parts and corresponding icons: Expectations - This points to the set of knowledge and skills that you will learn after completing the module. Pretest - This measures your prior knowledge about the lesson at hand. Recap - This part of the module provides a review of concepts and skills that you already know about a previous lesson. Lesson - This section discusses the topic in the module. Activities - This is a set of activities that you need to perform. Wrap-Up - This section summarizes the concepts and application of the lesson. Valuing - This part integrates a desirable moral value in the lesson. Posttest – This measures how much you have learned from the entire module. EXPECTATIONS After going through with this self-learning module, you are expected to: 1. describe the effect of solute concentration to the colligative properties of solutions. 2. explain what happens when two solutions of different concentrations are separated by semi permeable membrane: and 3. cite the importance of osmosis to living things by giving examples. PRETEST Direction: Choose the letter of the best answer: 1. Which of the following statements about the effect of concentration of solution to the properties of solution is NOT correct? A. The greater the concentration of the solute, the fewer the molecules of solvent in it. B. The vapour pressure of solution containing a non-volatile solute is always lower than the vapour pressure of the pure solvent. C. The vapour pressure of non-volatile solute will depend on the concentration of the solution. D. The greater the concentration of the solute in the solution, the greater the molecules of solvent in it. 2. A cell in hypotonic solution A. loses water C. B. gains water D. 3. 4. neither gains or loses water gains or loses water equally Red blood cells are put into isotonic solution. What will happen when salt is added to the solution? A. the cell burst C. water enters the cell B. the cell crenate D. proteins pump salts into the cell Which of the following is the best description of a semipermeable membrane in the context of osmosis? A. A membrane that allows neither solute nor solvent particles to pass through it. B. A membrane that allows solute particles, but not solvent particles, to pass through it. C. A membrane that allows solvent particles, but not solute particles, to pass through it. D. A membrane that allows both solute and solvent particles to pass through it. 5. For ideal systems, the reduction in the chemical potential of solvent molecules upon the addition of solute depends only on which one of the following? A. The melting point of the solute. C. The solubility of the solute. B .The number of solute particles. D. The boiling point of the solute. RECAP Fill in the blanks. Choose the word or phrases from the word pool given below: 1. Some solutions conduct electricity because of the free flow of electrons in their structure. They are so called ______________. 2. ________ are those solutions in which the solute does not dissociate into ions when dissolved. 3. ______________ are properties that depend only on the number of solute particles in solution and not on the nature of the solute particles. 4. _________________ is the pressure exerted by a vapor in equilibrium with its condensed phase, either liquid or solid, at a particular temperature. 5. The boiling point of a liquid can be defined as the temperature at which the vapour pressure of the liquid is equal to ____________. 6. The difference in vapour pressures of the two solutions which are separated by a semipermeable membrane is called __________ 7. _____________ is the selective passage of a solvent molecule through a porous or semipermeable membrane from a diluted solution to a more concentrated solution. LESSON Have you ever tried to prepare homemade ice cream where there is no electricity? Did you put salt on the ice to cool the mixture of milk and sugar? The ice cream vendors also put salt on the ice chunks around the cans of the ice cream. What property of the salt makes it possible to make the ice colder? After studying this module, you will understand this phenomenon. Figure 1. Ice in Salt Ice Cream Making In your previous module, you have learned that colligative properties depend only on the number of solute particles in solution and not on the nature of the solute particles. They all depend on the number of solute particles present regardless, of whether they are atoms, ions or molecules. In dealing with solutions, it will be useful also to consider an ideal solution wherein solute-solute, solvent-solvent and solute interactions are in the same magnitude. In an ideal solution, the different molecules act independently of each other. When you determine the number of particles in a solution, it is very important that you always remember that not all solutions with the same molarity contain the same concentration of solute particles. For example, 0.01 M aqueous solutions of sucrose, NaCl, and CaCl 2. It is because, sucrose dissolves to give a solution of neutral molecules, the concentration of solute particles in a 0.01 M sucrose solution is 0.01 M. In contrast, both NaCl and CaCl2 are ionic compounds that dissociate in water to yield solvated ions. As a result, a 0.01 M aqueous solution of NaCl contains 0.01 M Na+ ions and 0.01 M Cl− ions, for a total particle concentration of 0.02 M. On the same way, the CaCl2 solution contains 0.01 M Ca 2+ ions and 0.02 M Cl− ions, for a total particle concentration of 0.03 M. Mg 2+ At higher concentrations especially with salts, highly charged ions just like or Al 3+, or in solutions with less polar solvents, dissociation is often incomplete to give separate ions. The sum of the concentrations of the dissolved solute particles determine the physical properties of a solution. In the succeeding discussion, you must therefore keep in mind the chemical nature of the solute. Let us consider for example an ideal solution of two components only. If the solute and solvent molecules are both volatile, the molecules will evaporate independently of each other. The vapour pressure of each component will depend upon the rate at which its molecules leave the surface. Now, this in turn, will depend upon the concentration of the molecules of each component on the surface of and within the liquid. The concentration of each component is decreased by the molecules of the other component. Therefore, each component in the solution will have a lower vapour pressure than that of the individual pure component. So, it means that the total vapour pressure of the solution will be the sum of the independent vapour pressure of the two components. If the solute is non-volatile, the vapor pressure of the solution will be that of the solvent only and will depend on its concentration. The greater the concentration of the solute in the solution, the fewer the solvent molecules will escape, and the lower will be the vapor pressure of the solution. The vapor pressure of a solution containing a non-volatile solute is always lower than the vapour pressure of the pure solvent. However, the vapour pressure of the solution will approach that of the pure solvent as the solution becomes more and more dilute. Like boiling point elevation and freezing point depression, osmotic pressure is directly proportional to the concentration of solution. This is what we will expect because all colligative properties depend only in the number of solute particles in the solution. If there are two solutions of equal concentration and hence, have the same osmotic pressure, they are said to be isotonic. If two solutions are of unequal osmotic pressures, the more concentrated solution is said to be hypertonic and the more dilute solution is described as hypotonic. Figure 2. Types of Solutions There are many interesting applications of osmotic pressure phenomenon. In order to study the contents of red blood cells, which are protected from the external environment by a semipermeable membrane, the biochemists use a technique called hemolysis. The red blood cell membrane is not permeable (passage through is not possible to sodium chloride). The red blood cells are placed in a hypotonic solution. Because the hypotonic solution is less concentrated than the interior of the cell, water moves into the cells. The cells swell and then eventually burst, releasing hemoglobin and other molecules. Any solution to be injected into the blood plasma must be isotonic with the cell fluid. This is insured by dissolving the material in a 0.87% salt solution known as physiological salt solution. Also, nasal sprays or drops are in isotonic solution to prevent swelling or shrinkage of the tissue of the nasal cavity when sprays or drops are applied. Other applications of osmotic pressure include home preserving of jam and jelly. A large quantity of sugar is actually necessary to the preservation process since sugar helps kill the bacteria that may cause botulism. When bacterial cell is in hypertonic (high concentration) sugar solution, the intracellular water tends to move out of the bacterial cell to the more concentrated solution by osmosis. We call this process as crenation, which causes the cell to shrink and eventually to cease functioning. Osmotic pressure is also in major mechanism in transporting water upward in plants. Because the leaves constantly lose water to the air, in the process called transpiration, the solute concentrations in leaf increase. Water is pulled up through the trunk, branches, and stems of tress. ACTIVITIES Activity 1. Match the terms in Column A with their characteristics in Column B and then with column C. Write your answers on the blank provided with you on the number before each number. COLUMN B COLUMN A ____1. solubility ____2. solute ____3. freezing point ____4. boiling point ____5. solvent ____6. electrolyte ____7. miscible ____8. osmotic pressure ____9. solution ____10. nonelectrolyte COLUMN C A. dissolving substance 1. B. form ions to conduct 2. electricity 3. sodium chloride C. temperature at which 4. 0 0 C liquids starts to solidify 5. oil in water D. homogeneous mixture 6. semipermeable E. proportional to molar concentration membrane F. mixes easily 7. acidic solution G. does not conduct electricity 8. 1000 C H. vapour pressure is equal to atmospheric 9. pressure H2 O I. measure the amount of solute 10. alcohol in J. dissolved substance water sugar solution water 36 g NaCl/ 100 g K. two opposing processes occur at equal rates Activity 2. Using the given clues, arrange and form the correct word/words with the jumbled letters 1. 2. 3. 4. 5. - LNIGBOI TOIPN _____________________ -the temperature at which the vapour pressure of the liquid equals the prevailing atmospheric pressure. TOSMOIC SPEURESR ___________________ the pressure needed to stop the net flow of solvent molecules in a situation where a solution is separated by a semipermeable membrane from a pure solvent. GZEFINER TPOIN ______________________ temperature at which solid and liquid are in equilibrium. TGILIVAOCLE ____________________ the properties which mean that they depend on the collective effect of the concentration of solute particles present in the solution. ROVAP SUPESERR ____________________ the pressure exerted by the gas that is in dynamic equilibrium with its liquid in closed system at a specific temperature. WRAP-UP Fill in the blanks. The most active component of the solution is the (1)____________ (solute, solvent). It has greater effect on the properties of a (2) __________(solute, solvent, solution) such as boiling temperature, freezing temperature, and (3) ________________ (boiling point, vapour pressure). (4) ________________ (Properties, Concentration) of a solution is expressed in (5)_______________(molarity, molality), rather than mole fractions is used in solving (6)___________________(boiling point elevation, freezing point expression). (7). _____________________(Osmosis, osmotic pressure) is the passage of a solvent molecule through a(8) ____________________ (permeable, semipermeable) membrane from a (9) _____________ ( diluted, concentrated) solution or from the solvent itself into a (10) ________________ (diluted, concentrated) solution. The (11) ____________ (greater, lesser) the concentration of the solute, the greater the (12) ___________(vapour pressure, osmotic pressure) of the solution. VALUING The knowledge about colligative properties of solution and concentration of solution are very useful in our daily living. Similarly, there are careers in which these knowledge is very useful, too. Just like the pharmacists, they are engaged in the preparation and distribution of drugs and medications. Another example is the perfumer. Perfumers mix solutions of ingredients, check to make sure that the ingredients are properly balanced, and test the fragrances. Can you cite other work or jobs in which concepts on solution concentrations are being applied? POSTTEST Choose the letter of the best answer: 1. Which of the following about the effect of concentration of solution to the properties of solution is correct? A. Since the vapour of a solution is always lower than that of pure solvent, the solvent in solution does not freeze at 0 0 C. B. The greater the concentration of the solute in the solution, the greater the molecules of solvent in it. C. For the vapour pressure of the solvent to be equal to the vapour pressure of solid solvent, the solution need to be cooled at higher temperature. D. The diffusion of the solvent molecules is from lower to higher concentration. 2. The solution with ________ solvent concentration has a higher vapour pressure than the other solution. A. greater B. lower C. slower D. cannot be determined 3. The difference in solute concentration between two areas or regions is called A. hypotonic C. absolute difference B. hypertonic D. concentration gradient 4. A wilted plant tissue placed in cold water becomes stiffer and harder because A. plasmolysis has occurred. B. water has passed into the cells C. the cell has gained cellulose D. the cell’s salt concentration has increased 5. Osmotic pressure is important in biological processes. What do you think will happen if a salt solution were to be poured on a plant? A. It will grow fast because more nutrients will be obtained from salt solution. B. The plant will dry up and die since water will flow out of the roots because salt solution is concentrated. C. The plant will become acidic making it healthier. D. The plant will obtain water from other parts of the plants. References n.d. http://www.chemteam.info/GasLaw/Gas-graham Prob1-10html. Accessed August 2020. n.d. https//opentextc.ca/chemistry/chapter/9-4-eusion-and-difusion o gas. Accessed August 2020. n.d. https://courses.Lumenlearning.com/suny-mcc-chemistryfor majors-1/chapter/efusion-anddiffusion-of-gas/. Accessed August 2020. Ilao, Luciana V., Betty M. Lontoc, Edwehna Elinore S. Paderna-Gayon, and Josefina G. Belen. 2016. General Chemistry 1. Manila: Rex Book Store. Maderal, Chona, Ma. Cristina C. Domingo, and Roberto V. Anir. 2005. CHEMISTRY Skills Builder and Exercises. Quezon City: Great Minds Book Sales, Inc. Nudo, Leogarda P., Zaidy B. Mindo, Nenita T. Villamarin, and Jocelyn A. Prado. 2009. SKILLBOOSTER.COM SkillBook in Chemistry. Quezon City: Bookman, Inc. https://2012books.lardbucket.org/books/principles-of-general-chemistryv1.0/s08-03-stoichiometry-of-reactions-in-.html https://opentextbc.ca/chemistry/chapter/11-4-colligative-properties/ https://opentextbc.ca/introductorychemistry/chapter/colligative-properties-ofsolutions-2/
