CHEM 1211 Lecture 12Outline of Last Lecture I. Problem OneII. Problem TwoIII. Dilution of SolutionA. Problem OneIV. Chemical ThermodynamicsA. Heat Transfer1. Through a Liquid…Outline of Current Lecture I. Acid Concentrations1. Example One2. Example Two3. Example Three (CQ #1)4. Example Four 5. Example FiveII. Chemical ThermodynamicsA. Heat Transfer1. CQ #22. CQ #33. Example OneB. Internal Energy(NEW THERMODYNAMIC FXN)1. Example OneCurrent Lecture: I. Acid Concentrations1. Consider a 0.15M solution of hydrochloric acid. What is the pH?HCl(aq) + H2O(l) H3O+(aq) + Cl-(aq)pH= -log[H+ or H3O+]-log0.15=pH-0.823 x -1 =pH0.823 =pH0.82 =pH Acidic!!2. Consider a 0.15M solution of sulfuric acid. What is the pH?pH = -log[H3O+] = -log0.3 = -0.52 x -1 = 0.52pH Acidic!!!3. What is the pH of the sulfurous acid solution in the previous problem?1.84 x 10-3MpH = 2.735 or 2.734. What is the [H3O+] in a solution that has a pH of 8.677[H3O+]= 10-pH[H3O+]= 10-8.677 = 2.10 x 10-9M BASIC!!!5. What is the [H3O+] in a solution that has a pH of 2.144?[H3O+] = 10-2.144 = 7.18 x 10-3MII. Chemical ThermodynamicsA. Heat TransferqSystem + qSurroundings = 0qSurroundings = -qSystemq= m x C x T- As, T1 As, T2T2= melting/freezing pointq= m x Cs x T- As, T2 Al, T2Melting: q=m x HfusionTemperature doesn’t change- Al, T2 Al, T3T3= boiling point endothermic exothermicq= m x Cliquid x T- Al, T3 Ag, T3q=m x Hvaporization1. CQ #2Which has the highest specific heat?2. CQ #3What is not physically possible?q= heat (J or KJ)m= massC= specific heat T = change in tempTEMPHeat AddedTEMP3. 2.56 mL of ethylene glycol is at 25.00°C. How much heat must be transferred to change it into a gas at 212.0°C?B. Internal Energy(NEW THERMODYNAMIC FXN) U = qp + Wp U = qp – P Vqp = U + P V1. 2C8H18(l) + 25O2(g) 16CO2(g) + 18H2O(l)H°= -136.6 KJ/ mol-rxnWhat is the enthalpy change if you burn 1.00L of isooctane (D= 0.690g/mL)?1.00L 103mL 0.690g mol C8H181 mol-rxn -136.6KJ = L mL 114g C8H182 mol C8H18mol-rxn-4.13 x 102 KJ: exothermicSystem: RXNHeat
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