{"id":3354,"date":"2023-10-05T07:55:32","date_gmt":"2023-10-05T07:55:32","guid":{"rendered":"http:\/\/localhost\/ecole9ja\/?p=3354"},"modified":"2023-10-05T08:03:51","modified_gmt":"2023-10-05T08:03:51","slug":"week-2-ss2-third-term-chemistry-notes","status":"publish","type":"post","link":"https:\/\/ecolebooks.com\/nigeria\/posts\/week-2-ss2-third-term-chemistry-notes\/","title":{"rendered":"Week 2 &#8211; SS2 Third Term Chemistry Notes"},"content":{"rendered":"<p>\u00a0<strong>WEEK TWO<br \/>\n<\/strong><strong>TOPIC: SOLUBILITY AND SOLUTIONS<br \/>\n<\/strong><strong>CONTENT<br \/>\n<\/strong><\/p>\n<ul>\n<li>Definition of Terms.\n<\/li>\n<li>Calculations based on Solubility.\n<\/li>\n<li>Solubility Curves.\n<\/li>\n<li>\n<div>Uses of Solubility.\n<\/div>\n<p>\u00a0<strong>SOLUTIONS<br \/>\n<\/strong>A solution is a uniform or homogenous mixture of two or more substances.<br \/>\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Solution = Solvent + Solute<br \/>\nA solute is a dissolved substance which may be a solid, liquid or gas.<br \/>\nA solvent is a substance (usually liquid) which dissolves a solute.\n<\/li>\n<\/ul>\n<p>\u00a0<strong>TYPES OF SOLUTIONS<br \/>\n<\/strong><\/p>\n<ol>\n<li>Aqueous Solution: This is formed when a solute is dissolved in water.\n<\/li>\n<li>\n<div>Chemical Solution: This is the apparent solution of a solute in a solvent accompanied by a chemical change. For example, magnesium appears to dissolve in dilute hydrochloric acid, what actually happens is that the magnesium attacks the acid to form magnesium chloride, which dissolves in water present.\n<\/div>\n<p>\u00a0<strong>TRUE SOLUTION AND COLLOIDAL SOLUTION<br \/>\n<\/strong><\/li>\n<\/ol>\n<p>A true solution is formed when solute particles dissolve such that they are able to get in between the solvent particles. Example of true solution is aqueous solution of sodium chloride and copper (II) tetraoxosulphate (VI).<br \/>\nA False or Colloidal solution is one in which the individual particles are larger than the particles of a true solution, but not large enough to be seen by the naked eye. Examples of colloids are starch and albumen.<\/p>\n<p>\u00a0<strong>TYPES OF COLLOIDS<br \/>\n<\/strong><\/p>\n<ol>\n<li>Sols and Gels: These are colloids where solid particles are dispersed in liquid medium. Example: starch, glue, jelly, etc\n<\/li>\n<li>Aerosols: In aerosols, liquid particles are dispersed in a gas. Fog, smoke, spray of insecticide is examples of aerosol.\n<\/li>\n<li>\n<div>Emulsion: For emulsions, a liquid is dispersedin another liquid. Examples of emulsions are milk, hair cream; cleaning action of detergents is due to their ability to form emulsion.\n<\/div>\n<p>\u00a0<strong>EVALUATION<\/strong>\n\t\t\t<\/li>\n<li>Define the term &#8216;Solution&#8217;.\n<\/li>\n<li>\n<div>State THREE differences between True solution and False solution.\n<\/div>\n<p>\u00a0<strong>SOLUBILITY<br \/>\n<\/strong><\/li>\n<\/ol>\n<p>The solubility of a solute (substance) in a solvent at a particular temperature is the maximum amount of solute in moles or grams that will dissolve in 1 dm<sup>3<\/sup> of the solvent at that temperature.<\/p>\n<p>\u00a0<img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100523_0755_Week2SS2Th1.png\" alt=\"\"\/>The concentration in moldm<sup>-3<\/sup> of a saturated solution is termed the solubility of the substance i.e. Solubility (moldm<sup>3<\/sup>) = Concentration in gdm<sup>3<\/sup><br \/>\n\t\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Molar mass<br \/>\nSolubility in mol\/dm<sup>3<\/sup> can also be expressed as = mass x  \u00a0\u00a0\u00a0\u00a01000<br \/>\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Molar mass      volume<br \/>\nSolubility in g\/dm<sup>3<\/sup> = mass   x\u00a0\u00a0\u00a0\u00a01000<br \/>\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0volume\u00a0\u00a0\u00a0\u00a01<br \/>\nSolubility of a solid solute in a solvent increases with rise in temperature while solubility of gases decreases with rise in temperature.\u00a0\u00a0\u00a0\u00a0<\/p>\n<p>\u00a0<strong>DEFINITION OF TERMS<br \/>\n<\/strong><\/p>\n<ol>\n<li>\n<div>Saturated Solution: A saturated solution at a particular temperature is one which contains as much solute as it can dissolves at that temperature in the presence of undissolved solute particles.\n<\/div>\n<\/li>\n<li>\n<div>Unsaturated solution: This is a solution which contains less of the solute than it can dissolve at a particular temperature.\n<\/div>\n<\/li>\n<li>\n<div>Super saturated solution: This is a solution which contains more of the solute than it can dissolve at a particular temperature.\n<\/div>\n<p>\u00a0<\/li>\n<\/ol>\n<p><strong>EVALUATION<\/strong><\/p>\n<ol>\n<li>\n<div>Define Solubility\n<\/div>\n<\/li>\n<li>\n<div>Differentiate between Saturated solution and Unsaturated solution\n<\/div>\n<\/li>\n<\/ol>\n<p>\u00a0<strong>DETERMINATION OF SOLUBILITY<br \/>\n<\/strong>Solute: KCl, Solvent: water<br \/>\n<strong>Method<br \/>\n<\/strong><\/p>\n<ol>\n<li>\n<div>A saturated solution of KCl is prepared by dissolving excess of the solid in water in a beaker\n<\/div>\n<\/li>\n<li>\n<div>Allow the solution in the beaker to settle down to obtain a clear saturated solution\n<\/div>\n<\/li>\n<li>\n<div>Decant a portion of clear solution into another beaker and measures its temperature\n<\/div>\n<\/li>\n<li>\n<div>Transfer the solution into a weighed evaporation dish and record the mass of the solution\n<\/div>\n<\/li>\n<li>\n<div>Evaporate the solution to a complete dryness in a water bath\n<\/div>\n<\/li>\n<li>\n<div>Allow the resulting solid to cool and reweigh the basin with content\n<\/div>\n<\/li>\n<li>\n<div>Obtain mass of the dissolved salt and calculate the mass of the salt that would dissolve in 1dm<sup>3<\/sup> of water at that temperature.\n<\/div>\n<p>\u00a0<strong>CALCULATION<br \/>\n<\/strong>Mass of basin\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0=\u00a0\u00a0\u00a0\u00a0xg<br \/>\nMass of basin + solution\u00a0\u00a0\u00a0\u00a0=\u00a0\u00a0\u00a0\u00a0yg<br \/>\nMass of basin  + salt\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0=\u00a0\u00a0\u00a0\u00a0zg<br \/>\nMass of solution\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0=\u00a0\u00a0\u00a0\u00a0(y-x)g<br \/>\nMass of salt\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0=\u00a0\u00a0\u00a0\u00a0(z-x)g<br \/>\nMass of water used\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0=\u00a0\u00a0\u00a0\u00a0(y-z)g<br \/>\n:. (y \u2013 z)g H<sub>2<\/sub>O dissolves (z \u2013 x)g salt<br \/>\n:.  100g H<sub>2<\/sub>O dissolves (z \u2013 x)\/(y \u2013 z) x 100g salt<br \/>\n[Density of water   =  1gcm<sup>3<\/sup>]<br \/>\n<img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100523_0755_Week2SS2Th2.png\" alt=\"\"\/>:.  No of moles of salt\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0=\u00a0\u00a0\u00a0\u00a0100(z \u2013 x)<br \/>\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0(y-z) x M.M<\/p>\n<p>\u00a0<img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100523_0755_Week2SS2Th3.png\" alt=\"\"\/>:.  Moles of salt dissolves in 1 dm<sup>3<\/sup> water = 100(z-x)<br \/>\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0(y-z) x M.M<\/p>\n<p>\u00a0<strong>FACTORS THAT AFFECT SOLUBILITY<br \/>\n<\/strong><\/li>\n<\/ol>\n<p>1.\u00a0\u00a0\u00a0\u00a0Nature of solvent and solute<br \/>\n2.\u00a0\u00a0\u00a0\u00a0Temperature<br \/>\n3.\u00a0\u00a0\u00a0\u00a0Pressure (often neglected)<\/p>\n<p>\u00a0<strong>SOLUBILITY CURVES<br \/>\n<\/strong>These are the graphs of solubility against temperature.  The graph provides useful source of information.<\/p>\n<p>\u00a0<strong>USES OF SOLUBILITY CURVES<br \/>\n<\/strong>1.\u00a0\u00a0\u00a0\u00a0It provides useful information about suitable solvent and temperature for solvent extraction from natural sources<br \/>\n2.\u00a0\u00a0\u00a0\u00a0It provides useful information about temperature for fractional crystallization of a mixture of soluble salts.<br \/>\n3.\u00a0\u00a0\u00a0\u00a0The curves enable pharmacists to determine the amount of solid drugs that must be dissolved in a given quantity of solvent to give a prescribed drug mixture.<\/p>\n<p>\u00a0<strong>EVALUATION<\/strong><br \/>\n\t1.\u00a0\u00a0\u00a0\u00a0Define super-saturated solution<br \/>\n2.\u00a0\u00a0\u00a0\u00a0State two applications of solubility curves<\/p>\n<p>\u00a0<strong>CALCULATION ON SOLUBILITY<br \/>\n<\/strong>1.\u00a0\u00a0\u00a0\u00a0If 12.2g of Pb(NO<sub>3<\/sub>)<sub>2<\/sub> were dissolved in 21cm<sup>3 <\/sup>of distilled water at 20<sup>o<\/sup>C.  Calculate the solubility of the solute in moldm<sup>-3<\/sup><\/p>\n<p>\u00a0Solution<strong>:<br \/>\n<\/strong>Molar mass of Pb(NO<sub>3<\/sub>)<sub>2<\/sub> = 331g<br \/>\n\u00a0\u00a0\u00a0\u00a0No of moles of Pb(NO<sub>3<\/sub>)<sub>2<\/sub>  =  12.2\/331 = 0.037moles<br \/>\n\u00a0\u00a0\u00a0\u00a0If 21cm<sup>3<\/sup> of water at 20<sup>0<\/sup>C dissolved 0.037mole salt<br \/>\n\u00a0\u00a0\u00a0\u00a0:. 1000cm<sup>3<\/sup> of water at 20<sup>0<\/sup>C dissolves 0.037 x 1000\/21<br \/>\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0= 176moles Pb(NO<sub>3<\/sub>) per dm<sup>3<\/sup> H<sub>2<\/sub>O<\/p>\n<p>\u00a02.\u00a0\u00a0\u00a0\u00a01.0dm<sup>3 <\/sup>of an aqueous solution at 90<sup>o<\/sup>C contains 404g of KNO<sub>3<\/sub> and 245g of KClO<sub>3<\/sub>.<br \/>\na. Determine which of the two salts will separate out when the solution is cooled to  60<sup>o<\/sup>C<br \/>\nb. mass of salt that will separate out at 60<sup>o<\/sup>C<br \/>\n(Solubility of KNO<sub>3<\/sub> in H<sub>2<\/sub>O at 60<sup>o<\/sup>C = 5.14moldm<sup>-3<\/sup>, solubility of KClO<sub>3<\/sub> in H<sub>2<\/sub>O at 60<sup>o<\/sup>C = 1.61moldm<sup>-3<\/sup>)<\/p>\n<p>\u00a0Solution:<br \/>\nNo of moles of KNO<sub>3<\/sub> = 404\/101 = 4.0moles dm<sup>-3<\/sup><br \/>\n\tNo of moles of KClO<sub>3<\/sub> = 245\/122.5 = 2.0 moldm<sup>-3<\/sup><br \/>\n\tThe solubility of KClO<sub>3<\/sub> at 60<sup>o<\/sup>C (5.14 moldm<sup>-3<\/sup>) is higher than the amount in solution (4.0 moldm<sup>-3<\/sup>), then KNO<sub>3<\/sub> will remain in solution while KClO<sub>3<\/sub> will crystallize out at 60<sup>o<\/sup>C since the solubility at 60<sup>o<\/sup>C is lower than the amount in solution.<\/p>\n<p>\u00a0b. Mass of salt that will separate out at 60<sup>o<\/sup>C = 2.0 \u2013 1.61 = 0.39mole<br \/>\n     Mass of salt = Number of moles x Molar mass<br \/>\n    = 0.39 x 122.5 = 47.78g<\/p>\n<p>\u00a03.\u00a0\u00a0\u00a0\u00a0The solubility of KNO<sub>3<\/sub> is exactly 1800g per 1000g water at 83<sup>o<\/sup>C and 700g per 1000g water at 40<sup>o<\/sup>C.  Calculate the mass of KNO<sub>3<\/sub> that will crystallize out of solution if 155g of the saturated solution at 83<sup>o<\/sup>C is cooled to 40<sup>o<\/sup>C.<\/p>\n<p>\u00a0Solution:<br \/>\nSaturated solution of KNO<sub>3<\/sub> at 83<sup>o<\/sup>C = 1000 + 1800 = 2800g<br \/>\nSaturated solution of KNO<sub>3 <\/sub>at 40<sup>o<\/sup>C = 1000 + 700 = 1700g<br \/>\nMass of solute deposited = 2800 \u2013 1700 = 1100g<br \/>\nFrom 83<sup>o<\/sup>C to 40<sup>o<\/sup>C, 2800 of saturated solution deposited 1100g of solute<br \/>\n155g of saturated solution will deposit 1100 x 155\/2800 = 60.80g of salt.<\/p>\n<p>\u00a0<strong>EVALUATION<\/strong><\/p>\n<ol>\n<li>\n<div>Define the following terms: Solubility, Saturated solution, Unsaturated solution.\n<\/div>\n<\/li>\n<li>\n<div>1.33 dm<sup>3<\/sup> of water at 70<sup>o<\/sup>C are saturated by 2.25 moles of lead (II) trioxonitrate (V) and 1.33 dm<sup>3<\/sup> of water at 18oc are saturated by 0.53 mole of the same salt. If 4.50dm<sup>3<\/sup> of the saturated solution are cooled from 70<sup>o<\/sup>C to 18<sup>o<\/sup>C, calculate the mount of solute that will be deposited in (a) moles (b) grams.\n<\/div>\n<\/li>\n<\/ol>\n<p>\u00a0<strong>GENERAL EVALUATION\/REVISION<br \/>\n<\/strong><\/p>\n<ol>\n<li>\n<div>Calculate the solubility of KCl in g\/dm<sup>3<\/sup> if 5g of the salt was dissolved in 50cm<sup>3<\/sup> of water at 40<sup>o<\/sup>C\n<\/div>\n<\/li>\n<li>\n<div>If 50cm<sup>3<\/sup> of a saturated solution of potassium chloride at 30<sup>o<\/sup>C yielded 18.62g of dry salt, calculate the solubility of the salt in mol\/dm<sup>3<\/sup> at 30<sup>o<\/sup>C\n<\/div>\n<\/li>\n<li>\n<div>Define solubility\n<\/div>\n<\/li>\n<li>\n<div>A certain mass of a gas occupies 300cm<sup>3<\/sup> at 35<sup>o<\/sup>C. At what temperature will it have its volume reduced by half, assuming its pressure remains constant?\n<\/div>\n<\/li>\n<li>\n<div>A certain mass of hydrogen gas collected over water at 10oc and 760mm Hg pressure has a volume of 37cm<sup>3<\/sup>. Calculate the volume when it is dry at s.t.p. (Saturated vapour pressure of water at 10<sup>o<\/sup>C = 9.2mmHg)\n<\/div>\n<p>\u00a0<br \/>\n\u00a0<strong>READING ASSIGNMENT<br \/>\n<\/strong><\/li>\n<\/ol>\n<p>New School Chemistry for Senior Secondary School by O.Y.Ababio (6<sup>th<\/sup>edition) pages 303-310 <\/p>\n<p>\u00a0<strong>WEEKEND ASSIGNMENT<br \/>\n<\/strong><strong>SECTION A: <\/strong>Write the correct option ONLY<\/p>\n<ol>\n<li>\n<div>A saturated solution is a solution a. in which the solute is in equilibrium with the solvent b. in which the solute saturates the solution c. the solvent can still accept more solute except when the temperature is lowered d. whose solvent has low solubility at a given temperature\n<\/div>\n<ol>\n<li>\n<div>A graph of solubility against temperature is called a. sigmoid curve\n<\/div>\n<\/li>\n<\/ol>\n<p>b. supernant curve c. solubility curve d. dispersion curve\n<\/li>\n<li>\n<div>On heating 25g of a saturated solution to dryness at 60<sup>o<\/sup>C, 4g of anhydrous salt was recovered. Calculate its solubility in g\/dm<sup>3<\/sup>. a. 160 b. 180 c. 200 d. 220\n<\/div>\n<\/li>\n<li>\n<div>The solubility of alcohols in water is due to a. their covalent nature b. hydrogen bonding c. their low boiling point d. their ionic character\n<\/div>\n<\/li>\n<li>\n<div>A common solvent of sulphur is a. water b. carbon(IV)sulphide c. alcohol d. ethanoic acid\n<\/div>\n<\/li>\n<\/ol>\n<p>\u00a0<strong>SECTION B<br \/>\n<\/strong>1.\u00a0\u00a0\u00a0\u00a0Define the following:<br \/>\n\u00a0\u00a0\u00a0\u00a0(a) Solubility (b) Saturated solution (c) Unsaturated solution<br \/>\n2. \u00a0\u00a0\u00a0\u00a0If the solubility of KNO<sub>3<\/sub> at 0<sup>o<\/sup>C is 1.33mol\/dm<sup>3<\/sup>, determine whether a solution containing 30.3g\/dm3 at 0<sup>o<\/sup>C is saturated or unsaturated.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u00a0WEEK TWO TOPIC: SOLUBILITY AND SOLUTIONS CONTENT Definition of Terms. Calculations based on Solubility. Solubility&#8230;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1,268],"tags":[],"class_list":["post-3354","post","type-post","status-publish","format-standard","hentry","category-posts","category-third-term-ss2-chemistry"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/ecolebooks.com\/nigeria\/wp-json\/wp\/v2\/posts\/3354","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=3354"}],"version-history":[{"count":1,"href":"https:\/\/ecolebooks.com\/nigeria\/wp-json\/wp\/v2\/posts\/3354\/revisions"}],"predecessor-version":[{"id":3355,"href":"https:\/\/ecolebooks.com\/nigeria\/wp-json\/wp\/v2\/posts\/3354\/revisions\/3355"}],"wp:attachment":[{"href":"https:\/\/ecolebooks.com\/nigeria\/wp-json\/wp\/v2\/media?parent=3354"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ecolebooks.com\/nigeria\/wp-json\/wp\/v2\/categories?post=3354"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ecolebooks.com\/nigeria\/wp-json\/wp\/v2\/tags?post=3354"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}