Moles

StudyBlue printing of Moles html, body, div, span, applet, object, iframe, h1, h2, h3, h4, h5, h6, p, blockquote, pre, a, abbr, acronym, address, big, cite, code, del, dfn, em, font, img, ins, kbd, q, s, samp, small, strike, strong, sub, sup, tt, var, b, u, i, center, fieldset, form, label, legend, table, caption, tbody, tfoot, thead, tr, th, td { margin: 0; padding: 0; border: 0; outline: 0; font-size: 100%; background: transparent; } body { line-height: 1; } blockquote, q { quotes: none; } blockquote:before, blockquote:after, q:before, q:after { content: ''; content: none; } /* remember to define focus styles! */ :focus { outline: 0; } /* remember to highlight inserts somehow! */ ins { text-decoration: none; } del { text-decoration: line-through; } /* tables still need 'cellspacing="0"' in the markup */ table { border-collapse: collapse; border-spacing: 0; } /* end RESET */ .header { min-width:800px; } .logo { padding:6px 20px 2px 20px; margin:0; font-size:25px; font-weight:bold; color:#808285; position:relative; border-bottom: 1px solid #c5c5c5; } .logo-blue { color:#70adc4; } .logo-desc { font-weight:normal; font-size:19px; color:#cccccc; margin-top:50px; position:absolute; display: none; } .back-button { position:absolute; top:20px; right:20px; font-size:13px; line-height:25px; color:rgb(0,175,225); font-weight:normal; } .back-button a { color:rgb(0,175,225); } .instructions { padding:0; margin:0; width:100%; position:relative; color:rgb(100,100,100); } .step-holder { border-left:1px solid #ededed; margin-left:20px; } .steps { padding:15px 0; float:left; width:24%; border-right:1px solid #ededed; text-align:center; } .steps-01 { } .steps-02 { } .steps-03 { } .steps-04 { } .label { padding:5px 10px; } .print-button { } .print-button a { background-color:rgb(0,175,225); color:white; line-height: 19px; padding:9px 8px 5px 30px; font-size:14px; text-decoration:none; background-image: url(images/printer.png); background-repeat: no-repeat; background-position: 7px 50%; -moz-border-radius: 5px; -webkit-border-radius: 5px; } .print-button a:hover { background-color:black; } .theNote .content { width: 8.0in !important; margin: 5px auto; padding:20px; background-color:white; } .theNote .header { border-bottom: 1px dashed #C8C8C8; font-size: 17px; padding: 0 0 10px; line-height: 19px; color: #00ADE1; min-width:500px; } .theNote .body { font-size: 14px; line-height: 19px; padding: 10px 0; } .theNote{ padding:6px 0; clear:both; background-color: rgb(200,200,200); } .theNote h3{ color: rgb(100,100,100); } .theNote h1, .theNote h3{ background-color:white; padding:2px 20px; width:8.0in !important; margin: 0 auto; font-size: 15px; } .theNote h1{ padding-top: 10px; font-size: 15px; } .theNote h1:first-child{ font-size: 20px; } .theNote h3 { font-size: 14px; font-weight: normal; } #options { border: 3px double #ccc; padding: 5px 12px; margin: 10px 50px 10px 20px; float: left; } #info { border-top: 1px solid #ccc; padding-top: 5px; font-style: italic; } li { margin: 5px 10px 5px 25px; } ul li { list-style: disc; } ol li { list-style: decimal; } img { border: 0; } table { clear: both; width: 100%; border: 1px solid #c5c5c5; border-width: 1px 0; margin: 0; page-break-after: always; } table#page { page-break-after: auto; } td { text-align: center; font-size: 12px; border-bottom: 1px dashed #c5c5c5; height: 1.75in; width: 50%; padding-left: 15px; } .leftside { border-right: 1px solid #cccccc; padding: 0 15px 0 0; } .bottom td { border-bottom: none; } .clearfix { clear:both; line-height:1px; height:1px; } img { max-width:80%; max-height:150px; margin:20px; } @media print {.header { display: none; } .content .header{ display:inherit; } table { border: 1px dashed #bbb; border-width: 1px 0; } .theNote{ background-color:white; } } Converting Between Moles and Particles Counting Numbers Gross = 144 Score = 20 Ream = 500 Mole = 6.02 x 10 23 ( Avagadro's Number ) Which particles go with which substance? Repr. Part. Substances Atoms Elements Ions Ion Molecules Covalent Compound (CO 2 ) Formula Unit Ionic Compound (NaCl) Converting Moles to Representative Particles RepPart = Moles x (6.02 x 10 23 RepPart) / (1 Mole) Example: .250 moles of silver 0.250 mol silver x (6.02 x 10 23 atoms) / (1 Mole) = 1.51 x 10 23 atoms (3 sig figs) ***DON'T FORGET TO USE SIG FIGS *** Converting Representative Particles to Moles Moles = RepPart x (1 Mole) / (6.02 x 10 23 RepPart) Example: 1.56 x 10 23 formula units of NaOH 1.56 x 10 23 formula units NaOH (1 Mole) / (6.02 x 10 23 FU) = .259 mols (3 sig figs) Molar Mass Molar Mass = Mass in grams of 1 mole of a substance, unit = grams/moles Molar Mass of an element is given on the periodic table For compounds, just add the molar masses of all the elements in the compound and multiply by the number of atoms of each element Example: CaCO3 40.08 + 12.01 + 3(15.99) = 100.06 g/mol If given grams of a compound: Find molar mass of compound, multiply grams by 1/molarmass to get number of moles If given moles of a compound: Find molar mass of compound, multiply number of moles by molarmass/1 to get number of grams Volume STP = 273 Kelvin and 1 atm pressure For gases at STP, 1 mol occupies a volume of 22.4 L Example: 100 g of O 2 100g x 1mol/32g = 3.125 moles 3.125 x 22.4 = 70 L If given a formula and grams of a substance: convert to moles then use proportions to find moles of other substances, then multiply by 22.4 Percentage Composition Find the molar mass of each element Find the molar mass of the compound Divide the mm of the compound by the mm of the element to find what % of the composition that indv. element is Example: KMnO 4 Molar Mass of compound = 158.03 g/mol Molar Mass of Mn = 54.93 Thus, Mn composes 34.76% of the compound Empirical Formulas Empirical Formula - A formula that gives the simplest whole-number ratio of the atoms of the elements Molecular Formula - The formula that gives the actual number of atoms of each element in a molecular compound Example: E = P 4 O 6 , M= P 2 O 3 How to write the empirical formula when given composition: Divide percent of element by molar mass of element to get a ratio Multiply to get the ratio to whole numbers Whole number ratio = subscripts of compound How to write the molecular formula when given the empirical and mass (e.g. P2O5 weighing 283.89g) Find mass of empirical formula (141.94) Divide given mass of compound by empirical mass to get X (x=283/141=2) Multiply subscripts by X (2*2, 5*2 --> P4O10) Interpreting Balanced Chemical Equations Ratio of coefficients can be applied to moles, representative particles, and volume but NOT mass Mass-Mass Determine molar mass of both compounds Set up proportion: Grams/Molarmass of known = x/Molarmass of unknown Multiply molarmass in denominator by coefficient if they are not equal Solve for X for number of grams Example - 2AgNO3 + BaCl2 --> ... Find grams of BaCl2 given 5.0 g of AgNO3 BaCl2 Molarmass = 207 AgNO3 Molarmass = 169 5/169 = x/207 (still need to account for coefficients) 5/(2*169) = x/207 (now they are accounted for) X = 3.06g of BaCl2 Volume-Volume Mole-ratios = Volume-ratios Example - N2 + 3H2 --> 2NH3, find liters ammonia given 5 liters nitrogen Ratio 1:3:2 Multiply ratio by 5 = 5:15:10 Answer is 10L