{"id":2040,"date":"2023-10-02T08:39:37","date_gmt":"2023-10-02T08:39:37","guid":{"rendered":"http:\/\/localhost\/ecole9ja\/?p=2040"},"modified":"2023-10-02T08:43:01","modified_gmt":"2023-10-02T08:43:01","slug":"week-9-ss1-first-term-chemistry-notes-2","status":"publish","type":"post","link":"https:\/\/ecolebooks.com\/nigeria\/posts\/week-9-ss1-first-term-chemistry-notes-2\/","title":{"rendered":"Week 9 &#8211; SS1 First Term Chemistry Notes"},"content":{"rendered":"<p><strong>WEEK 9<br \/>\n<\/strong><strong>MIXTURES AND SEPERATION TECHNIQUES<br \/>\n<\/strong>A <strong>mixture<\/strong> is made from different substances that are <strong>not chemically joined<\/strong>.<br \/>\nFor example powdered iron and powdered sulphur mixed together makes a mixture of iron and sulphur. They can be separated from each other without a chemical reaction, in the way that different coloured sweets can be picked <\/p>\n<p>\u00a0out from a mixed packet and put into separate piles.<br \/>\n<img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100223_0839_Week9SS1Fi1.gif\" alt=\"\"\/><br \/>\n\t\t<strong>Mixture and compounds<br \/>\n<\/strong>Mixtures have different properties from compounds. The table summarises these differences.<br \/>\n<strong>\u00a0\u00a0\u00a0\u00a0\u00a0Mixture\u00a0\u00a0\u00a0\u00a0Compound<br \/>\n<\/strong><strong>Composition<\/strong>\u00a0\u00a0\u00a0\u00a0Variable composition \u2013 you can vary the amount of each substance in a mixture. \u00a0\u00a0\u00a0\u00a0Definite composition \u2013 you cannot vary the amount of each element in a compound.<br \/>\n<strong>Joined or not<\/strong>\u00a0\u00a0\u00a0\u00a0The different substances are not chemically joined together.\u00a0\u00a0\u00a0\u00a0The different elements are chemically joined together.<br \/>\n<strong>Properties<\/strong>\u00a0\u00a0\u00a0\u00a0Each substance in the mixture keeps its own properties. \u00a0\u00a0\u00a0\u00a0The compound has properties different from the elements it contains.<br \/>\n<strong>Separation<\/strong>\u00a0\u00a0\u00a0\u00a0Each substance is easily separated from the mixture.\u00a0\u00a0\u00a0\u00a0It can only be separated into its elements using chemical reactions.<br \/>\n<strong>Examples<\/strong>\u00a0\u00a0\u00a0\u00a0Air, sea water, most rocks.\u00a0\u00a0\u00a0\u00a0Water, carbon dioxide, magnesium oxide, sodium chloride.<br \/>\n<strong>An example &#8211; iron, sulphur and iron sulphide<br \/>\n<\/strong>Remember that iron and sulphur react together when they are heated to make a compound called iron sulphide. What are the differences between a mixture of iron and sulphur, and iron sulphide? Here are some of them:<\/p>\n<ul>\n<li>\n<div>The mixture can contain more or less iron, but iron sulphide always contains equal amounts of iron and sulphur.\n<\/div>\n<\/li>\n<li>\n<div>The iron and sulphur atoms are not joined together in the mixture, but they are joined together in iron sulphide.\n<\/div>\n<\/li>\n<li>\n<div>The iron and sulphur still behave like iron and sulphur in the mixture, but iron sulphide has different properties from both iron and sulphur.\n<\/div>\n<\/li>\n<li>\n<div>You can separate the iron from the mixture using a magnet but this does not work for iron sulphide.\n<\/div>\n<\/li>\n<\/ul>\n<p>\u00a0<br \/>\n\u00a0<strong>SEPARATION OF MIXTURES USING DIFFERENT TECHNIQUES<br \/>\n<\/strong><br \/>\n\u00a0<strong>Our Objective<br \/>\n<\/strong>To separate the components of a mixture using the following techniques:<\/p>\n<ul>\n<li>\n<div><strong>Separating funnel<\/strong>\n\t\t\t\t<\/div>\n<\/li>\n<li>\n<div><strong>Chromatography<\/strong>\n\t\t\t\t<\/div>\n<\/li>\n<li>\n<div><strong>Centrifugation<\/strong>\n\t\t\t\t<\/div>\n<\/li>\n<li>\n<div><strong>Simple distillation<\/strong>\n\t\t\t\t<\/div>\n<\/li>\n<li>\n<div><strong>Fractional distillation<\/strong>\n\t\t\t\t<\/div>\n<\/li>\n<\/ul>\n<p><strong>The Theory<br \/>\n<\/strong><strong>How is a homogeneous mixture different from a heterogeneous mixture?<br \/>\n<\/strong>Most materials in our surroundings are mixtures of two or more components. Mixtures are either <strong>homogeneous<\/strong> or <strong>heterogeneous. Homogeneous mixtures are uniform in composition<\/strong>, but <strong>heterogeneous mixtures are not uniform in composition.<\/strong><br \/>\n\t\tAir is a homogeneous mixture and oil in water is a heterogeneous mixture. Homogeneous and heterogeneous mixtures can be separated into their components by several physical methods. The choice of separation techniques is based on the type of mixture and difference in the chemical properties of the constituents of a mixture.<br \/>\n<strong>What are types of separation techniques?<br \/>\n<\/strong><strong>Various types of separation processes are:\u00a0<\/strong><\/p>\n<ul>\n<li>\n<div><strong>Crystallization<\/strong>\n\t\t\t\t<\/div>\n<\/li>\n<li>\n<div><strong>Filtration<\/strong>\n\t\t\t\t<\/div>\n<\/li>\n<li>\n<div><strong>Decantation<\/strong>\n\t\t\t\t<\/div>\n<\/li>\n<li>\n<div><strong>Sublimation<\/strong>\n\t\t\t\t<\/div>\n<\/li>\n<li>\n<div><strong>Evaporation<\/strong>\n\t\t\t\t<\/div>\n<\/li>\n<li>\n<div><strong>Simple distillation<\/strong>\n\t\t\t\t<\/div>\n<\/li>\n<li>\n<div><strong>Fractional distillation<\/strong>\n\t\t\t\t<\/div>\n<\/li>\n<li>\n<div><strong>Chromatography<\/strong>\n\t\t\t\t<\/div>\n<\/li>\n<li>\n<div><strong>Centrifugation<\/strong>\n\t\t\t\t<\/div>\n<\/li>\n<li>\n<div><strong>Separating funnel<\/strong>\n\t\t\t\t<\/div>\n<\/li>\n<li>\n<div><strong>Magnetic separation<\/strong>\n\t\t\t\t<\/div>\n<\/li>\n<li>\n<div><strong>Precipitation<\/strong>\n\t\t\t\t<\/div>\n<\/li>\n<\/ul>\n<p><strong>Let&#8217;s discuss some of the separation techniqueS<br \/>\n<\/strong><strong>Using a separating funnel: <\/strong><br \/>\n\t\t<strong>A separating funnel is used for the separation of components of a mixture between two immiscible liquid phases.<\/strong> One phase is the aqueous phase and the other phase is an organic solvent. This separation is based on the differences in the densities of the liquids. The liquid having more density forms the lower layer and the liquid having less density forms the upper layer.<br \/>\n<strong>Applications: <\/strong>\u00a0<\/p>\n<ul>\n<li>\n<div>To separate a mixture of oil and water.\n<\/div>\n<\/li>\n<li>\n<div>To separate a mixture of kerosene oil and water.\n<\/div>\n<\/li>\n<\/ul>\n<p><strong>Chromatography: <\/strong><br \/>\n\t\t<strong>Chromatography is a separation technique used to separate the different components in a liquid mixture.<\/strong> It was introduced by a Russian Scientist Michael Tswett. <strong>Chromatography involves the sample being dissolved in a particular solvent called mobile phase<\/strong>. The mobile phase may be a gas or liquid. The mobile phase is then passed through another phase called stationary phase. The stationary phase may be a solid packed in a glass plate or a piece of chromatography paper.<br \/>\nThe various components of the mixture travel at different speeds, causing them to separate. There are different types of chromatographic techniques such as column chromatography, TLC, paper chromatography, and gas chromatography.<br \/>\nPaper chromatography is one of the important chromatographic methods. Paper chromatography uses paper as the stationary phase and a liquid solvent as the mobile phase. In paper chromatography, the sample is placed on a spot on the paper and the paper is carefully dipped into a solvent. The solvent rises up the paper due to capillary action and the components of the mixture rise up at different rates and thus are separated from one another.<br \/>\n<img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100223_0839_Week9SS1Fi2.png\" alt=\"\"\/><br \/>\n\t\t\u00a0<br \/>\n\u00a0<strong>Applications: <\/strong>\u00a0<\/p>\n<ul>\n<li>\n<div>To separate colors in a dye.\n<\/div>\n<\/li>\n<li>\n<div>To separate pigments from natural colors.\n<\/div>\n<\/li>\n<li>\n<div>To separate drugs from blood.\n<\/div>\n<\/li>\n<\/ul>\n<p><img decoding=\"async\" align=\"right\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100223_0839_Week9SS1Fi3.png\" alt=\"\"\/><strong>Centrifugation:<\/strong><br \/>\n\t\tSometimes the solid particles in a liquid are very small and can pass through a filter paper. For such particles, the filtration technique cannot be used for separation. Such mixtures are separated by centrifugation. So, <strong>centrifugation is the process of separation of insoluble materials from a liquid where normal filtration does not work well.<\/strong> The centrifugation is based on the size, shape, and density of the particles, viscosity of the medium, and the speed of rotation. The principle is that the denser particles are forced to the bottom and the lighter particles stay at the top when spun rapidly.<br \/>\nThe apparatus used for centrifugation is called a centrifuge. The centrifuge consists of a centrifuge tube holder called rotor. The rotor holds balanced centrifugal tubes of equal amounts of the solid-liquid mixture. On rapid rotation of the rotor, the centrifuge tubes rotate horizontally and due to the centrifugal force, the denser insoluble particles separate from the liquid. When the rotation stops, the solid particles end up at the bottom of the centrifuge tube with liquid at the top.<br \/>\n<strong>Applications:<\/strong>\u00a0<\/p>\n<ul>\n<li>\n<div>Used in diagnostic laboratories for blood and urine tests.\n<\/div>\n<\/li>\n<li>\n<div>Used in dairies and home to separate butter from cream.\n<\/div>\n<\/li>\n<li>\n<div>Used in washing machines to squeeze water from wet clothes.\n<\/div>\n<\/li>\n<\/ul>\n<p><strong>Simple distillation: <\/strong><br \/>\n\t\t<strong>Simple distillation is a method used for the separation of components of a mixture containing two miscible liquids that boil without decomposition and have sufficient difference in their boiling points.<\/strong><br \/>\n\t\tThe distillation process involves heating a liquid to its boiling points, and transferring the vapors into the cold portion of the apparatus, then condensing the vapors and collecting the condensed liquid in a container. In this process, when the temperature of a liquid rises, the vapor pressure of the liquid increases. When the vapor pressure of the liquid and the atmospheric pressure reach the same level, the liquid passes into its vapor state. The vapors pass over the heated portion of the apparatus until they come into contact with the cold surface of the water-cooled condenser. When the vapor cools, it condenses and passes down the condenser and is collected into a receiver through the vacuum adapter.<br \/>\n<img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100223_0839_Week9SS1Fi4.png\" alt=\"\"\/><br \/>\n\t\t\u00a0<strong>Applications: <\/strong>\u00a0<\/p>\n<ul>\n<li>\n<div>Separation of acetone and water.\n<\/div>\n<\/li>\n<li>\n<div>Distillation of alcohol.\n<\/div>\n<\/li>\n<\/ul>\n<p><strong>Fractional distillation:Fractional distillation is used for the separation of a mixture of two or more miscible liquids for which the difference in boiling points is less than 25K.<\/strong> The apparatus for fractional distillation is similar to that of simple distillation, except that a fractionating column is fitted in between the distillation flask and the condenser.<br \/>\nA simple fractionating column is a tube packed with glass beads. The beads provide surface for the vapors to cool and condense repeatedly. When vapors of a mixture are passed through the fractionating column, because of the repeated condensation and evaporation, the vapors of the liquid with the lower boiling point first pass out of the fractionating column, condense and are collected in the receiver flask. The other liquid, with a slightly higher boiling point, can be collected in similar fashion in another receiver flask.<br \/>\n<img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100223_0839_Week9SS1Fi5.png\" alt=\"\"\/><br \/>\n\t\t<strong>Applications: <\/strong>\u00a0<\/p>\n<ul>\n<li>\n<div>Separation of different fractions from petroleum products.\n<\/div>\n<\/li>\n<li>\n<div>Separation of a mixture of methanol and ethanol.\n<\/div>\n<\/li>\n<\/ul>\n<p>\u00a0<br \/>\n\u00a0<\/p>\n<h2>Separating solids from liquids \u2013 evaporation<br \/>\n<\/h2>\n<p>Evaporation is used to separate a soluble solid from a liquid. For example, copper sulfate is soluble in water \u2013 its crystals dissolve in water to form copper sulfate solution. During evaporation, the water evaporates away leaving solid copper sulfate crystals behind.<br \/>\n<img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100223_0839_Week9SS1Fi6.png\" alt=\"\"\/><br \/>\n\t\tA solution is placed in an evaporating basin and heated with a Bunsen burner.<\/p>\n<h2>Separating solids from liquids \u2013 filtration<br \/>\n<\/h2>\n<p>If a substance does not dissolve in a solvent, we say that it is insoluble. For example, sand does not dissolve in water \u2013 it is insoluble.<br \/>\nFiltration is a method for separating an insoluble solid from a liquid. When a mixture of sand and water is filtered:<\/p>\n<ul>\n<li>\n<div>the sand stays behind in the filter paper (it becomes the residue)\n<\/div>\n<\/li>\n<li>\n<div>the water passes through the filter paper (it becomes the filtrate)\n<\/div>\n<\/li>\n<\/ul>\n<p><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100223_0839_Week9SS1Fi7.png\" alt=\"\"\/><br \/>\n\t\tA beaker containing a mixture of insoluble solid and liquid. There is filter paper in a filter funnel above another beaker.<br \/>\n<img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100223_0839_Week9SS1Fi8.gif\" alt=\"\"\/>\u00a0\u00a0\u00a0\u00a0<img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100223_0839_Week9SS1Fi9.gif\" alt=\"\"\/><\/p>\n<ul>\n<li>\n<div>components in a mixture retain their identities\n<\/div>\n<\/li>\n<li>\n<div>exploit properties that distinguish the components to separate mixtures\n<\/div>\n<p>Some manufacturers add iron filings to cereal to increase its iron content! The bits of iron will stick to a magnet, but the cereal won&#8217;t. So you can easily separate the mixture by stirring a bar magnet through a slurry of water and finely crushed cereal.<br \/>\nthe more similar the properties are, the more difficult it is to separate them<br \/>\nMany elements occur in forms with slightly different masses. For example, uranium occurs as uranium-235, which can be used to construct atomic bombs, and uranium-238, which can&#8217;t. The two are very difficult to separate because they are nearly identical otherwise. The technical difficulties in separating this mixture is one of the factors that has limited the proliferation of nuclear weapons.\n<\/li>\n<li>\n<div>basic strategies\n<\/div>\n<ul>\n<li>\n<div>phase conversion: convert components of the mixture into other forms that are easy to isolate\n<\/div>\n<\/li>\n<li>\n<div>phase transfer: add a new phase that collects some components from the mixture, but not others\n<\/div>\n<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<div>\n<table>\n<tbody>\n<tr>\n<td><strong>technique<\/strong><\/td>\n<td><strong>basis for separation<\/strong><\/td>\n<td><strong>apply this technique to:<\/strong><\/td>\n<\/tr>\n<tr>\n<td>adsorption \/ desorption<\/td>\n<td>phase transfer to a solid surface<\/td>\n<td>liquid or gaseous mixtures that contain at least one component that adsorbs<\/td>\n<\/tr>\n<tr>\n<td>chromatography<\/td>\n<td>phase transfer from a mobile mixture to a stationary phase<\/td>\n<td>liquid or gaseous solutions that contain several components with differing affinities for the stationary phase<\/td>\n<\/tr>\n<tr>\n<td>condensation<\/td>\n<td>phase separation by condensing gases in the mixture to liquids<\/td>\n<td>gaseous mixtures containing at least one gas with a much higher boiling point than the others <\/td>\n<\/tr>\n<tr>\n<td>dialysis<\/td>\n<td>phase transfer through a porous membrane that allows some molecules to pass through, but not others<\/td>\n<td>solutions containing small molecules mixed with very large molecules<\/td>\n<\/tr>\n<tr>\n<td>effusion<\/td>\n<td>gases with faster molecules flow through tiny pinholes faster than gases with slow molecules <\/td>\n<td>gaseous mixtures containing gases with different molecular weights<\/td>\n<\/tr>\n<tr>\n<td>dissolution (washing, solvent extraction)<\/td>\n<td>soluble components can be washed away, leaving behind insoluble components (phase transfer to a washing solvent)<\/td>\n<td>mixtures of solids with different solubilities<\/td>\n<\/tr>\n<tr>\n<td>electrorefining<\/td>\n<td>separate a metal from impurities by dissolving it and then plating it onto an electrode <\/td>\n<td>solid mixtures with a metal as one component <\/td>\n<\/tr>\n<tr>\n<td>filtration<\/td>\n<td>collect solid particles on a filter <\/td>\n<td>heterogeneous mixture containing a solid phase<\/td>\n<\/tr>\n<tr>\n<td>floatation<\/td>\n<td>dense components sink, and lighter ones float<\/td>\n<td>heterogeneous mixture with phases with different densities<\/td>\n<\/tr>\n<tr>\n<td>ion exchange<\/td>\n<td>ions in the mixture bind to surfaces with oppositely charged sites (phase transfer to an ion exchange resin)<\/td>\n<td>solutions containing ions<\/td>\n<\/tr>\n<tr>\n<td>precipitation<\/td>\n<td>convert solutes to an easily separated solid form<\/td>\n<td>solutions containing a solute that can be precipitated<\/td>\n<\/tr>\n<tr>\n<td>scrubbing<\/td>\n<td>bubble mixture through a solution that selectively absorbs a component (phase transfer from gas to solution)<\/td>\n<td>gaseous mixtures containing a solute that can be selectively absorbed by a scrubbing solution<\/td>\n<\/tr>\n<tr>\n<td>stripping<\/td>\n<td>a gas bubbled through the mixture carries off the most volatile components<br \/>\n(phase transfer from solution to gas)<\/td>\n<td>a liquid mixture containing at least one volatile component<\/td>\n<\/tr>\n<tr>\n<td>volatilization<br \/>\n(drying, distillation, sublimation)<\/td>\n<td>components with widely differing volatility can be driven out of the mixture by heating (phase change from solid or liquid to gas)<\/td>\n<td>a mixture containing components with differing volatility<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<h3>Adsorption and desorption<br \/>\n<\/h3>\n<ul>\n<li>\n<div>some solids bind gases and organic materials to their surfaces, removing them from mixtures\n<\/div>\n<\/li>\n<li>\n<div>adsorbed gases or liquids can recovered from the adsorbent material by washing with a solvent\n<\/div>\n<\/li>\n<li>\n<div>examples\n<\/div>\n<ul>\n<li>\n<div>activated charcoal adsorbs many gases and liquids\n<\/div>\n<ul>\n<li>\n<div>used as a &#8220;universal antidote&#8221; for poisoning\n<\/div>\n<\/li>\n<li>\n<div>used in water purifiers (removes particulates, lead, copper, mercury, chlorine, hypochlorite, organics)\n<\/div>\n<\/li>\n<li>\n<div>used to adsorb drugs from the blood of overdose victims\n<\/div>\n<\/li>\n<\/ul>\n<\/li>\n<li>\n<div>silica gel absorbs moisture from air\n<\/div>\n<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<h3>Condensation<br \/>\n<\/h3>\n<ul>\n<li>\n<div>cooling a vapor causes components with the highest boiling points to condense as liquids first\n<\/div>\n<\/li>\n<li>\n<div>examples\n<\/div>\n<ul>\n<li>\n<div>separating steam and air\n<\/div>\n<\/li>\n<li>\n<div>separating oxygen and nitrogen in air\n<\/div>\n<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<h3>Dialysis\u00a0\u00a0\u00a0\u00a0<br \/>\n<\/h3>\n<ul>\n<li>\n<div>a semipermeable membrane allows some components in a mixture through, but not others\n<\/div>\n<\/li>\n<li>\n<div>how does the membrane distinguish components?\n<\/div>\n<ul>\n<li>\n<div>some membranes act as a &#8220;molecular sieve&#8221; that discriminates between large and small molecules\n<\/div>\n<\/li>\n<li>\n<div>some membranes dissolve one component better than others\n<\/div>\n<\/li>\n<li>\n<div>development of new membranes is an active area of research in industry and government\n<\/div>\n<\/li>\n<\/ul>\n<\/li>\n<li>\n<div>components flow spontaneously from the high concentration to low concentration side\n<\/div>\n<ul>\n<li>\n<div>pressure applied to the low concentration side can stop or even reverse this flow (<em>reverse osmosis<\/em>)\n<\/div>\n<\/li>\n<\/ul>\n<\/li>\n<li>\n<div>examples\n<\/div>\n<ul>\n<li>\n<div>purification of blood in dialysis machines\n<\/div>\n<\/li>\n<li>\n<div>purification of seawater by reverse osmosis\n<\/div>\n<\/li>\n<li>\n<div>separation of pollutants from drinking water\n<\/div>\n<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<h3>Effusion<br \/>\n<\/h3>\n<ul>\n<li>\n<div>use porous membranes to separate light gases from heavy ones\n<\/div>\n<ul>\n<li>\n<div>average speed of gas molecules depends on the masses of their molecules\n<\/div>\n<\/li>\n<li>\n<div>heavy molecules in a mixture move slower on average than light ones\n<\/div>\n<\/li>\n<li>\n<div>gases made of light molecules diffuse through pores in membranes faster than heavy molecules\n<\/div>\n<\/li>\n<\/ul>\n<\/li>\n<li>\n<div>differences from dialysis\n<\/div>\n<ul>\n<li>\n<div>membrane is permeable, not semipermeable: all gas molecules in the mixture can pass through it\n<\/div>\n<\/li>\n<li>\n<div>size of molecules isn&#8217;t usually important: pores in membrane are <em>much<\/em> larger than gas molecules\n<\/div>\n<\/li>\n<li>\n<div>&#8230;molecular velocity (and so, molecular mass) is the basis for separation, not size\n<\/div>\n<\/li>\n<\/ul>\n<\/li>\n<li>\n<div>examples\n<\/div>\n<ul>\n<li>\n<div>separating helium from oxygen\n<\/div>\n<\/li>\n<li>\n<div>separating uranium isotopes as volatile UF<sub>6<\/sub>\n\t\t\t\t\t\t<\/div>\n<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<h3>Dissolution (washing)<br \/>\n<\/h3>\n<ul>\n<li>\n<div>separate solids by washing away those that are soluble\n<\/div>\n<\/li>\n<li>\n<div>examples\n<\/div>\n<ul>\n<li>\n<div>separating sand and salt by water washing\n<\/div>\n<\/li>\n<li>\n<div>separating feldspars from quartz in rocks by washing with hot concentrated phosphoric acid\n<\/div>\n<\/li>\n<li>\n<div>separating organic stains from clothing by washing with organic solvents (dry cleaning)\n<\/div>\n<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<h3>Electrorefining<br \/>\n<\/h3>\n<ul>\n<li>\n<div>used to separate metals from impurities\n<\/div>\n<\/li>\n<li>\n<div>strategy\n<\/div>\n<ul>\n<li>\n<div>dissolve the impure metal\n<\/div>\n<\/li>\n<li>\n<div>plate it on an electrode, using a strong electric current\n<\/div>\n<\/li>\n<li>\n<div>pure metal deposits on the electrode, and the impurities stay in solution\n<\/div>\n<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<h3>Filtration<br \/>\n<\/h3>\n<ul>\n<li>\n<div>pass a mixture that contains solid particles through a porous filter\n<\/div>\n<\/li>\n<li>\n<div>if pores are smaller than particles, solid particles stay on filter and liquid\/gaseous components pass through\n<\/div>\n<\/li>\n<li>\n<div>often used after separation by precipitation\n<\/div>\n<\/li>\n<\/ul>\n<h3>Ion exchange<br \/>\n<\/h3>\n<ul>\n<li>\n<div>used to separate ions from mixtures\n<\/div>\n<\/li>\n<li>\n<div>pass the mixture over a surface that is covered with charged sites\n<\/div>\n<\/li>\n<li>\n<div>some ions stick to the charged sites\n<\/div>\n<\/li>\n<li>\n<div>examples\n<\/div>\n<ul>\n<li>\n<div>water deionization\n<\/div>\n<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<h3>Precipitation<br \/>\n<\/h3>\n<ul>\n<li>\n<div>precipitation is the conversion of a solute to solid form by chemical or physical change\n<\/div>\n<\/li>\n<li>\n<div>solids are then separated by filtration or floatation\n<\/div>\n<\/li>\n<li>\n<div>examples\n<\/div>\n<ul>\n<li>\n<div>separating mud and bacteria from water\n<\/div>\n<ul>\n<li>\n<div>a gooey aluminum hydroxide precipitate is formed in the water to carry particulates and bacteria to the bottom of a vat\n<\/div>\n<\/li>\n<li>\n<div>clean water is drawn off the top\n<\/div>\n<\/li>\n<\/ul>\n<\/li>\n<li>\n<div>separating sulfate ions from water by adding barium ions\n<\/div>\n<ul>\n<li>\n<div>barium ion + sulfate = insoluble barium sulfate\n<\/div>\n<\/li>\n<\/ul>\n<\/li>\n<li>\n<div>water softening with washing soda\n<\/div>\n<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<p>carbonate + calcium ion = insoluble calcium carbonate <\/p>\n<h3>Scrubbing<br \/>\n<\/h3>\n<ul>\n<li>\n<div>scrubbing is bubbling a gas stream through a solution that traps some components\n<\/div>\n<\/li>\n<li>\n<div>examples\n<\/div>\n<ul>\n<li>\n<div>CO<sub>2<\/sub> can be separated from air by bubbling it through a solution of barium hydroxide\n<\/div>\n<\/li>\n<li>\n<div>H<sub>2<\/sub>S can be removed from air by bubbling it through a zinc acetate solution\n<\/div>\n<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<h3>Solvent extraction<br \/>\n<\/h3>\n<ul>\n<li>\n<div>a component moves into a solvent shaken with the mixture\n<\/div>\n<\/li>\n<li>\n<div>works best with solvents that dissolve only one component Solvent extraction can be used to extract vanillin from vanilla beans. Shaking the beans with an organic solvent like chloroform transfers organic compounds (including the vanillin) to the chloroform. Shaking the chloroform with a sodium hydroxide solution transfers the vanillin into the sodium hydroxide solution.\n<\/div>\n<\/li>\n<\/ul>\n<h3>Stripping<br \/>\n<\/h3>\n<ul>\n<li>\n<div>a stream of gas bubbled through the mixture will carry off the most volatile components\n<\/div>\n<p>Blowing air through a straw in a glass of soda will cause it to go flat, because the air carries off the volatile carbon dioxide.\n<\/li>\n<li>\n<div>volatile components can be reclaimed from the gas by scrubbing\n<\/div>\n<\/li>\n<\/ul>\n<h3>Volatilization<br \/>\n<\/h3>\n<ul>\n<li>\n<div>heating a mixture can cause low-boiling components to volatilize (vaporize)\n<\/div>\n<\/li>\n<li>\n<div>several variations\n<\/div>\n<\/li>\n<li>\n<div>distillation is collecting and condensing volatilized components\n<\/div>\n<p>Alcohol can be separated from fermented corn mash by heating the mash to vaporize the alcohol. The vapor is collected and passed through coils of copper tubing, where it cools and condenses as a liquid once again. Moonshiners sometimes used old car radiators for the condensation step; the soldered joints added a toxic quantity of lead to the shine!\n<\/li>\n<li>\n<div>drying is complete volatilization of some components in the mixture\n<\/div>\n<p>Separation of water from clothes on a clothesline is one obvious example. The separation of salt from seawater using evaporating pools is another.\n<\/li>\n<li>\n<div>sublimation is volatilization of a solid (without melting!)\n<\/div>\n<p>Dry ice (solid carbon dioxide) is probably the most familiar example of a solid that sublimes. But water ice can also be converted directly into water vapor without melting, at low pressure. Snow on mountain peaks disappears without moistening the soil.<br \/>\nSeparation by sublimation is sometimes called &#8216;freeze drying&#8217;. Instant coffee is manufactured by freeze drying. (Boiling the coffee destroys the delicate molecules that give coffee its flavor, and so does exposure to air after a certain time, so distillation or simple drying isn&#8217;t used). Fresh coffee is frozen to form a mixture of ice and coffee crystals. The pressure over the mixture is lowered so that the ice sublimates, leaving the coffee crystals behind.\n<\/li>\n<\/ul>\n<p>Bottom of Form<\/p>\n<p>\u00a0<strong>EVALUATION<br \/>\n<\/strong><\/p>\n<ol>\n<li>\n<div><strong>Define and give one example each of i. A homogenous mixture and ii. A heterogenous mixture.<br \/>\n<\/strong><\/div>\n<\/li>\n<li>\n<div><strong>Define the following terms.i. filtrate ii. distillate  iii sublimate<br \/>\n<\/strong><\/div>\n<\/li>\n<li>\n<div><strong>How would you separate a mixture of salt and sand?Explain.<br \/>\n<\/strong><\/div>\n<\/li>\n<li>\n<div><strong>How would you separate the component of black ink.<br \/>\n<\/strong><\/div>\n<\/li>\n<li>\n<div><strong>List and explain all the separation techniques .Describe their industrial application.<br \/>\n<\/strong><\/div>\n<\/li>\n<\/ol>\n<p>\u00a0<strong>WEEK  10<br \/>\n<\/strong><strong>PRACTICALS ON SEPERATION TECHNIQUES<br \/>\n<\/strong><\/p>\n","protected":false},"excerpt":{"rendered":"<p>WEEK 9 MIXTURES AND SEPERATION TECHNIQUES A mixture is made from different substances that are&#8230;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1,167],"tags":[],"class_list":["post-2040","post","type-post","status-publish","format-standard","hentry","category-posts","category-first-term-ss1-chemistry"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/ecolebooks.com\/nigeria\/wp-json\/wp\/v2\/posts\/2040","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ecolebooks.com\/nigeria\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ecolebooks.com\/nigeria\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ecolebooks.com\/nigeria\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/ecolebooks.com\/nigeria\/wp-json\/wp\/v2\/comments?post=2040"}],"version-history":[{"count":1,"href":"https:\/\/ecolebooks.com\/nigeria\/wp-json\/wp\/v2\/posts\/2040\/revisions"}],"predecessor-version":[{"id":2041,"href":"https:\/\/ecolebooks.com\/nigeria\/wp-json\/wp\/v2\/posts\/2040\/revisions\/2041"}],"wp:attachment":[{"href":"https:\/\/ecolebooks.com\/nigeria\/wp-json\/wp\/v2\/media?parent=2040"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ecolebooks.com\/nigeria\/wp-json\/wp\/v2\/categories?post=2040"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ecolebooks.com\/nigeria\/wp-json\/wp\/v2\/tags?post=2040"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}