Solutions Science 7 Unit 1 Module 1 Science 7 Unit 1 Module 1: Solutions 2 Guess that Solution! Science 7 Unit 1 Module 1: Solutions 4 __ __ __ __ __ __ __ Science 7 Unit 1 Module 1: Solutions 5 V I N E G A R Science 7 Unit 1 Module 1: Solutions 6 __ __ __ __ __ Science 7 Unit 1 Module 1: Solutions 7 S U G A R Science 7 Unit 1 Module 1: Solutions 8 __ __ __ __ __ __ __ __ Science 7 Unit 1 Module 1: Solutions 9 G A S O L I N E Science 7 Unit 1 Module 1: Solutions 10 __ __ __ __ __ __ Science 7 Unit 1 Module 1: Solutions 11 P L A S M A Science 7 Unit 1 Module 1: Solutions 12 __ __ __ __ __ __ __ __ Science 7 Unit 1 Module 1: Solutions 13 M E T A L O R E Science 7 Unit 1 Module 1: Solutions 14 SOLUTIONS are homogeneous mixtures it may be solids dissolved in liquids or gases dissolved in liquids. There are also solutions where a gas is dissolved in another gas, a liquid in another liquid or a solid in another solid gaseous, liquid, and solid solutions are all around us. Many commercial products are sold as solutions. Science 7 Unit 1 Module 1: Solutions 15 Types of Solutions Science 7 Unit 1 Module 1: Solutions 16 Solutions are homogenous (looks the same) mixtures of substances in a single state. Solutions can exist in any phase and have certain properties.. Solutions can come in any phase (solid, liquid, gas). solution carries its own set of properties. Each 1. Solid solution - alloys - had to have been in the liquid phase at some point in time Bronze is an alloy consisting primarily of copper, commonly with about 12–12.5% tin and often with the addition of other metals (such as aluminum, manganese, nickel or zinc) and sometimes nonmetals or metalloids such as arsenic, phosphorus or silicon. Plastics are made up of polymers. These compounds contain atoms such as oxygen, nitrogen, or sulfur in their backbone chains, in addition to carbon. 2. Gaseous solution all mixtures of gases are solutions - each gas spread out uniformly in the space provided - gases diffuse through each other easily due to the space between the molecules - the properties of gaseous solutions are proportional to the percentages of the gases involved - Air Water Vapor Humid Air 3. Liquid solutions most solution exist in this form - the liquid is most commonly the solvent - the solute can be liquid, gas or solid - liquid solvents can usually only hold a certain amount of a solute - solutions containing water are said to be aqueous - water is the universal solvent - if ions are dissolved in the water the solution becomes an electrolyte - Salt + water alcohol + water + other substances Water + Powdered juice Nature of Solutions Science 7 Unit 1 Module 1: Solutions 23 Naturally Occurring Solutions examples are: natural bodies of water like the seas and ocean, blood plasma, air, and some mineral ores. Science 7 Unit 1 Module 1: Solutions 24 Manufactured/Processed Solutions such as vinegar which usually contains about 5% acetic acid in water. Some vinegar are clear homogeneous mixtures (solutions). Other kinds of vinegar are colloidal gasoline is a solution made up of different substances called hydrocarbons other examples of solutions that are processed include wine and liquor, brewed coffee and tea (but not instant tea). Science 7 Unit 1 Module 1: Solutions 25 Seatwork #1.1 Science 7 Unit 1 Module 1: Solutions 26 IDENTIFICATION. Classify if it is a natural or manufactured solution by checking the appropriate box. Then give its specific source or use. Write your answer in your notebook. Solutions Natural Manufactured Source/Use 1. Alcohol 2. Urine 3. Cooking Oil 4. Sweat 5. Shampoo Science 7 Unit 1 Module 1: Solutions 27 Activity #1.4 What are some properties of solutions? Science 7 Unit 1 Module 1: Solutions 28 Objectives: When you finish this activity you should be able to: 1.compare the evidence gathered with the predictions you made; and 2.describe some properties of solutions based on observations. Science 7 Unit 1 Module 1: Solutions 29 Science 7 Unit 1 Module 1: Solutions 30 Science 7 Unit 1 Module 1: Solutions 31 Science 7 Unit 1 Module 1: Solutions 32 Science 7 Unit 1 Module 1: Solutions 33 Science 7 Unit 1 Module 1: Solutions 34 Components of Solutions Solutions are made up of: 1) solute – material that is dissolved. (ex) salt 2) solvent – material that does the dissolving. (ex) water – most universal solvent Components of Solutions Solute – the component present in small amount Solvent – the component present in greater amount Science 7 Unit 1 Module 1: Solutions 36 Properties of Solutions Solutions are homogeneous. They are mixtures consisting of one phase only. The components are so well mixed that all parts of the solution appear the same. A solution has the same composition and properties throughout. Science 7 Unit 1 Module 1: Solutions 37 Properties of Solutions The solute cannot be separated from the solvent through filtration because these are so small that they pass through the filter paper or cheesecloth. Solutions do not scatter light. They do not exhibit Tyndall effect. Science 7 Unit 1 Module 1: Solutions 38 • The composition of the solute and solvent will determine whether a solute will dissolve or not. • There are several factors which determine how fast the solute will dissolve: – 1) Stirring (agitation) – the dissolving process occurs at the surface of the crystals that are being dissolved. Stirring speeds up the process because fresh solvent is continually brought into contact with the surface of the solute. Stirring only increases the rate, not the quantity that will be dissolved. Stirring will not make something dissolve that is not soluble. – 2) Temperature – As temperature increases, so does the rate of dissolving. The solvent particles have higher kinetic energy with increases in temperature. The higher the energy, the more collisions there are with the solute. – 3) Particle size – The smaller the particle size of the solute the faster the dissolving rate. The smaller the particle size, the larger the surface area which exposes more solute to be dissolved. Solubility - The solubility of a substance is the amount of solute that dissolves in a given quantity of solvent at a particle temperature. - Miscible – 2 liquids are miscible if they dissolve in all proportions in each other. - Immiscible – liquids that are insoluble in each other. Factors Affecting Solubility 1) Temperature - The solubility of most solid substances increases as the temperature of the solvent increases. 2) Pressure – Changes in pressure have little effect on the solubility of solids and liquids, but strongly effect the solubility of gases. - Gas solubility increases as the partial pressure of the gas above the solution increases. Solution Discriptions - Saturated solutions – contains the maximum amount of solute that can dissolve in a given amount of solvent for a particular temperature. The solute and solvent are in equilibrium. - Unsaturated solutions - A solution that can dissolve more solute at a given temperature. • Supersaturated – A solution that contains more solute than it can dissolve at a given temperature. • The crystallization of a supersaturated solution can be initiated if a very small crystal, called a seed crystal, of solute is added. Solution Concentrations Concentration: the amount (g) of solute dissolved in a specific amount of solvent 1. Concentrated: large amount of solute for the amount of solute. 2. Dilute: small amount of solute for the amount of solution. Methods of Determining Concentration of Solution: Concentration Ratios Concentration description Percent by mass Percent by volume Ratios mass of solute mass of solution x 100 volume of solute volume of solution x 100 Using Percent to Describe Concentration • Percent by mass usually describes solutions in which a solid is dissolved in a liquid. • Represents the ratio of the solute’s mass to the solution’s mass expressed as a percent. • The mass of solution equals the sum of the masses of the solute and solvent. Using Percent to Describe Concentration Calculating Percent by Mass Sample Problem #1: In order to maintain a sodium chloride concentration similar to ocean water, an aquarium must contain 3.6 g NaCl per 100g of water. What is the percent by mass of NaCl in the solution? Find mass of the solution. Mass of solution = g solute + g solvent = 3.6g + 100g = 103.6 g Using Percent to Describe Concentration Calculating Percent by Mass Sample Problem #1: In order to maintain a sodium chloride concentration similar to ocean water, an aquarium must contain 3.6 g NaCl per 100g of water. What is the percent by mass of NaCl in the solution? Substitute values into equation Percent by mass = mass of solute x 100 mass of solution = 3.6g ÷ 103.6g x 100 =3.5% Using Percent to Describe Concentration Calculating Percent by Mass Sample Problem #2: A one peso coin has a mass of 5.5 grams. How many grams of copper are in a one peso coin containing 75% copper by mass? Seatwork #1.2 1. A coin has mass of 6 grams of 4.8 grams of copper. Find the concentration of solution in percent. 2. 25% of chocolate powder added in 5.5 g of chocolate drink. Find the relative amount of solute. Using Percent to Describe Concentration Calculating Percent by Volume • describes solutions in which both the solute and solvent are liquids • Volume of the solution is the sum of the volumes of the solute and solvent Example: 70% isopropyl alcohol means that 70 volumes of alcohol are dissolved in 100 volumes of water, thus 30 volumes of water are in every 100 volumes of the isopropyl alcohol solution. Using Percent to Describe Concentration Calculating Percent by Volume Sample Problem #1: What is the percent by volume of ethanol in a solution that contains 35mL of ethanol dissolved in 155mL of water? Volume of solution = vol. solute + vol. solvent = 35mL + 155mL = 190mL = 35mL x 100 190mL =18.4% Using Percent to Describe Concentration Calculating Percent by Volume Sample Problem #2: How many mL of ethyl alcohol are present in a 50 mL bottle of a 70% alcohol solution? Seatwork #1.3 1. Find the rate of 70 mL isopropyl alcohol present in 100 mL rubbing alcohol. 2. A 5% solution of acetic acid was added to 250 mL of vinegar. Find the concentration of solute in volume.
