{"id":520,"date":"2017-08-21T10:01:12","date_gmt":"2017-08-21T10:01:12","guid":{"rendered":"http:\/\/americanboard.org\/Subjects\/chemistry\/?page_id=520"},"modified":"2017-09-13T06:22:06","modified_gmt":"2017-09-13T06:22:06","slug":"solution-interactions","status":"publish","type":"page","link":"https:\/\/americanboard.org\/Subjects\/chemistry\/solution-interactions\/","title":{"rendered":"Solution Interactions"},"content":{"rendered":"<div class=\"twelve columns\" style=\"margin-top: 10%;\">\n<div class=\"advance\">\n<p><a class=\"button button-primary\" href=\"http:\/\/americanboard.org\/Subjects\/chemistry\/solution-formation-and-concentrations\">\u2b05 Previous Lesson<\/a>\u00a0<a class=\"button\" href=\"http:\/\/americanboard.org\/Subjects\/chemistry\/gas-laws-and-solutions\">Workshop Index<\/a>\u00a0<a class=\"button button-primary\" href=\"http:\/\/americanboard.org\/Subjects\/chemistry\/colligative-properties-and-related-laws\">Next Lesson \u27a1<\/a><\/p>\n<\/div>\n<p><!-- UPDATE NEXT\/PREVIOUS ABOVE --><\/p>\n<p><!-- CONTENT STARTS HERE --><\/p>\n<h1 id=\"title\">Solution Interactions<\/h1>\n<h4>Objective<\/h4>\n<p>In this lesson we will examine how different types of particles interact in solutions, differentiate\u00a0between diffusion and osmosis, and see how to predict if precipitation will occur when solutions are\u00a0mixed.<\/p>\n<h4>Previously we covered&#8230;<\/h4>\n<ul>\n<li>To complete concentration calculations it is important to be comfortable working with percents and molar calculations.<\/li>\n<li>A solution is defined by the size of particles present.<\/li>\n<li>Solutions are formed when solute and solvent particles interact.<\/li>\n<li>Solution concentration can be expressed in a variety of ways including broad terms such as saturated, unsaturated, and supersaturated, as well as specific terms such as ppm, <img loading=\"lazy\" decoding=\"async\" class=\"no_margin\" src=\"http:\/\/americanboard.org\/Subjects\/Images\/chemistry\/img\/gaslaw\/s2_001.gif\" width=\"77\" height=\"41\" \/>, <img loading=\"lazy\" decoding=\"async\" class=\"no_margin\" src=\"http:\/\/americanboard.org\/Subjects\/Images\/chemistry\/img\/gaslaw\/s2_002.gif\" width=\"76\" height=\"44\" \/> molarity, and molality.<\/li>\n<li>Solution concentration can also be determined when a dilute solution is made from a stock solution by using <em>M<\/em><sub>1<\/sub><em>V<\/em><sub>1<\/sub><em> = M<\/em><sub>2<\/sub><em>V<\/em><sub>2<\/sub>.<\/li>\n<\/ul>\n<section>\n<h3>What Happens When Substances are Added to a Solution?<\/h3>\n<p>Interparticle interactions, sometimes called intermolecular forces, explain how substances interact\u00a0with each other. There are several different types of interparticle interactions with which we\u00a0should be familiar, including: ion-ion, ion-dipole, dipole-dipole, hydrogen bonds, and London\u00a0dispersion forces.<\/p>\n<ul>\n<li style=\"list-style-type: none;\">\n<ul>\n<li><abbr title=\"Atoms or group of atoms that have a positive or negative charge\">Ion<\/abbr>-ion\u00a0interactions are the strongest form of interparticle interactions. These occur when oppositely\u00a0charged gaseous ions in a vacuum are attracted to each other. As more collisions occur, larger\u00a0clusters of ions organize and can form a denser gas, a liquid, or even a solid.<\/li>\n<li>Ion-<abbr title=\"A portion of a molecule that is partially charged, having a positive region and\/or a negative region based on electron density \">dipole<\/abbr> interactions are interactions that occur between ions and polar compounds. They are not as\u00a0strong as ion-ion interactions. These interactions are particularly important to the dissolving\u00a0of salts in an aqueous solution. The positive sodium ions in sodium chloride are attracted to\u00a0the partially negative portion of the polar water molecule located around the oxygen. The\u00a0negative chloride ions are attracted to the partially positive portion of the water located in\u00a0the regions around the hydrogen atoms.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<p><center><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/americanboard.org\/Subjects\/Images\/chemistry\/img\/gaslaw\/solutioninteractions2.ion_dipole.gif\" alt=\"Ion Dipole Interactions\" width=\"212\" height=\"200\" \/><\/center><\/p>\n<ul>\n<li style=\"list-style-type: none;\">\n<ul>\n<li>Dipole-dipole interactions are attractions between molecules with dipoles. Dipole-dipole\u00a0interactions are weaker than ion-dipole interactions. A molecule like gaseous hydrogen chloride\u00a0has a pair of dipoles; the highly electronegative chlorine pulls the electron density close to\u00a0it creating a negative region around the chlorine. When the electron density is pulled away from\u00a0the hydrogen, it makes the region around the hydrogen partially positive. If two hydrogen\u00a0chloride molecules approach each other the oppositely charged dipoles are attracted to each\u00a0other. Dipole-dipole interactions are important in helping prevent some polar solvents from\u00a0vaporizing easily.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<p><center><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/americanboard.org\/Subjects\/Images\/chemistry\/img\/gaslaw\/solutioninteractions2.dipole_dipole.gif\" width=\"167\" height=\"150\" \/><\/center><\/p>\n<ul>\n<li>Hydrogen bonds are a special type of dipole-dipole interactions where a hydrogen atom involved\u00a0in a polar covalent bond is attracted to a highly <abbr title=\"The attraction of an atom for a shared pair of electrons\">electronegative<\/abbr> atom, usually fluorine, oxygen, or nitrogen, in another compound. Hydrogen bonding helps to\u00a0explain why hydrofluoric acid is a weak acid while HCl and HBr are strong acids.<\/li>\n<li>London dispersion forces are the very weak attractions between nonpolar covalent molecules of\u00a0the same type such as hydrogen, nitrogen, or diatomic halogens that allow us to liquefy or in\u00a0the case of iodine, solidify them. The temporary distortion of the electron cloud around an atom\u00a0causes a temporary dipole, which induces dipoles in other nearby molecules. These interactions\u00a0inhibit molecular movement as they are attracted to each other and account for the different\u00a0phases found in the halogens. London dispersion forces are the weakest of the interparticle\u00a0interactions.<\/li>\n<\/ul>\n<h3>Diffusion and Osmosis<\/h3>\n<p>Diffusion is a term often used to describe how one type of particle spreads through another. Here\u00a0particles move from areas of high concentration to low concentration. When walking through a\u00a0department store, it is usually easy to notice approaching the fragrance section because the scent\u00a0diffuses, or spreads, through the air in the store. The particles of low weight diffuse faster than\u00a0those that are heavier, as expressed in <abbr title=\"A gas will effuse at a rate that is inversely proportional to the square root of its molecular mass\">Graham\u2019s Law<\/abbr>.<\/p>\n<p>Osmosis on the other hand, describes the process by which solvent particles move through a <abbr title=\"A thin porous film that allows solvent particles to migrate through, but inhibits solute particles from passing through\">semipermeable membrane<\/abbr>. In osmosis, particles move from areas of low concentration to areas of higher concentration. When a pure solvent and a solution are placed in a container separated by a semipermeable membrane, the solvent particles will travel through the membrane and increase the amount of solution. The process of pickling cucumbers is a good example of osmosis where an area of low concentration (water inside the cucumber) passes through a semipermeable membrane (the \u201cskin\u201d of the cucumber) to a solution of higher concentration (the salt water solution used for pickling). The visible indicator of this process is the shrinkage of the cucumber as it becomes a pickle.<\/p>\n<h3>When Solutions are Mixed, Will a Precipitate Form?<\/h3>\n<p>When a salt dissolves in water its ionsdissociate. This process can happen very quickly or very slowly. As the ions form, some of them collide and reform the salt until equilibrium is achieved.<\/p>\n<p><center><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/americanboard.org\/Subjects\/Images\/chemistry\/img\/gaslaw\/s3_001.gif\" width=\"186\" height=\"24\" \/><\/center>From this equation the solubility product constant, K<sub>sp<\/sub>, can be written as:<\/p>\n<p><center><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/americanboard.org\/Subjects\/Images\/chemistry\/img\/gaslaw\/s3_002.gif\" width=\"104\" height=\"26\" \/><\/center>In order to determine if a precipitate will form, the K<sub>sp<\/sub> value must be compared to the\u00a0<abbr title=\"a measure of the conditions based on solution concentrations before equilibrium is established\">ion product <\/abbr>or\u00a0reaction quotient, <em>Q<\/em>. <em>Q<\/em> is found in the same way as K<sub>sp<\/sub>, except the\u00a0initial concentrations of the ions are used instead of the equilibrium concentrations.<\/p>\n<p>Conditions:<\/p>\n<ul>\n<li>When <em>Q<\/em> &gt; K<sub>sp<\/sub>, then a precipitate will form.<\/li>\n<li>When <em>Q<\/em> = K<sub>sp<\/sub>, then the solution is saturated.<\/li>\n<li>When <em>Q<\/em> &lt; K<sub>sp<\/sub>, then no precipitate forms.<\/li>\n<\/ul>\n<h4>Sample Problem<\/h4>\n<p>Will a precipitate form when 0.30 L of 0.0500 M Na<sub>2<\/sub>SO<sub>4<\/sub> and 0.20 L of 0.100 M\u00a0Pb(NO<sub>3<\/sub>)<sub>2<\/sub> are combined? The K<sub>sp<\/sub> of PbSO<sub>4<\/sub> is 6.3 \u00d7 10<sup>-7<\/sup>.<\/p>\n<p>To solve, find the concentration of both ions in the combined solution. The total volume of the\u00a0solution is equal to 0.20 L + 0.30 L = 0.50 L<\/p>\n<p><center><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/americanboard.org\/Subjects\/Images\/chemistry\/img\/gaslaw\/s3_003.gif\" width=\"564\" height=\"44\" \/><\/center><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/americanboard.org\/Subjects\/Images\/chemistry\/img\/gaslaw\/s3_004.gif\" width=\"616\" height=\"44\" \/><\/p>\n<p><center><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/americanboard.org\/Subjects\/Images\/chemistry\/img\/gaslaw\/s3_005.gif\" width=\"365\" height=\"25\" \/><\/center><\/p>\n<p><em> Q <\/em> is greater than K<sub>sp<\/sub>, therefore a precipitate will form.<\/p>\n<section class=\"question\">\n<h4>Question<\/h4>\n<p>Will a precipitate form when 0.010 L of 4.0\u00d710<sup>\u20133<\/sup> M sodium fluoride is mixed with\u00a00.020 L of 1.0\u00d710<sup>\u20132<\/sup> M calcium nitrate. The K<sub>sp<\/sub> of calcium fluoride is\u00a03.9\u00d710<sup>\u201311<\/sup>.<\/p>\n<ol>\n<li>Yes, because <em>Q<\/em> is greater than K<sub>sp<\/sub>.<\/li>\n<li>Yes, because <em>Q<\/em> is less than K<sub>sp<\/sub>.<\/li>\n<li>No, because <em>Q<\/em> is greater than K<sub>sp<\/sub>.<\/li>\n<li>No, because <em>Q<\/em> is less than K<sub>sp<\/sub>.<\/li>\n<\/ol>\n<p><a class=\"button button-primary q-answer\"> Reveal Answer <\/a><\/p>\n<p class=\"q-reveal\">The correct answer is A.<br \/>\n<img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/americanboard.org\/Subjects\/Images\/chemistry\/img\/gaslaw\/s3_008.gif\" width=\"220\" height=\"25\" \/><br \/>\nThe total volume of the solution is equal to 0.010 L + 0.020 L = 0.030 L<br \/>\n<img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/americanboard.org\/Subjects\/Images\/chemistry\/img\/gaslaw\/s3_009.gif\" width=\"605\" height=\"46\" \/><br \/>\n<img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/americanboard.org\/Subjects\/Images\/chemistry\/img\/gaslaw\/s3_010.gif\" width=\"618\" height=\"46\" \/><br \/>\n<img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/americanboard.org\/Subjects\/Images\/chemistry\/img\/gaslaw\/s3_011.gif\" width=\"409\" height=\"24\" \/><br \/>\n<em>Q <\/em>is greater than K<sub>sp<\/sub>, therefore a precipitate will form.<\/p>\n<\/section>\n<\/section>\n<p><!-- CONTENT ENDS HERE --><\/p>\n<p><!-- UPDATE NEXT\/PREVIOUS BELOW --><\/p>\n<div class=\"advance\"><a class=\"button button-primary\" href=\"http:\/\/americanboard.org\/Subjects\/chemistry\/solution-formation-and-concentrations\">\u2b05 Previous Lesson<\/a>\u00a0<a class=\"button\" href=\"http:\/\/americanboard.org\/Subjects\/chemistry\/gas-laws-and-solutions\">Workshop Index<\/a>\u00a0<a class=\"button button-primary\" href=\"http:\/\/americanboard.org\/Subjects\/chemistry\/colligative-properties-and-related-laws\">Next Lesson\u00a0\u27a1<\/a><\/div>\n<p><a class=\"backtotop\" href=\"#title\">Back to Top<\/a><\/p>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>\u2b05 Previous Lesson\u00a0Workshop Index\u00a0Next Lesson \u27a1 Solution Interactions Objective In this lesson we will examine how different types of particles interact in solutions, differentiate\u00a0between diffusion and osmosis, and see how to predict if precipitation will occur when solutions are\u00a0mixed. Previously we covered&#8230; To complete concentration calculations it is important to be comfortable working with percents [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-520","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/americanboard.org\/Subjects\/chemistry\/wp-json\/wp\/v2\/pages\/520","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/americanboard.org\/Subjects\/chemistry\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/americanboard.org\/Subjects\/chemistry\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/americanboard.org\/Subjects\/chemistry\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/americanboard.org\/Subjects\/chemistry\/wp-json\/wp\/v2\/comments?post=520"}],"version-history":[{"count":9,"href":"https:\/\/americanboard.org\/Subjects\/chemistry\/wp-json\/wp\/v2\/pages\/520\/revisions"}],"predecessor-version":[{"id":741,"href":"https:\/\/americanboard.org\/Subjects\/chemistry\/wp-json\/wp\/v2\/pages\/520\/revisions\/741"}],"wp:attachment":[{"href":"https:\/\/americanboard.org\/Subjects\/chemistry\/wp-json\/wp\/v2\/media?parent=520"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}