CHE-102 Lecture Outline Chapter 13 Info Not in Syllabus Lecture Recordings: 3 Buttons, 1 for each instructor In the Dr. Gulde’s TR Button: 1. 9:30am LIVE lecture 2. Dr. Gulde’s Pre-Lecture (PL) Videos button - Please watch prior to coming to lecture - Allows time in lecture for students to work sample problems - Embedded questions are not graded Location: Classroom Lecture Recordings → Recorded Lectures →Dr. Gulde’s TR lecture →Dr. Gulde’s PL-Videos Lecture Material: Each instructor as a folder In the Dr. Gulde’s Lecture Material Folder: 1. CHE102-Gulde Schedule-SP2024: more detailed than syllabus & has PL-Video due dates 2. Dr. Gulde’s Skeleton Outlines: to take notes if you wish 3. Gulde-Additional Problems: Extra problems for you to work 4. YouTube Videos: videos to help explain material Please bring to EVERY class Clicker device Outlines Calculator Periodic table © 2024 S. Gulde. Reproducing and distributing this material is prohibited. 1 CHE-102 Lecture Outline Chapter 13 Properties of Solutions Solutions Solutions – are ____________geneous (___________________________) mixtures Solute – usually present in _______________________ amounts, _____________ dissolving Solvent – usually present in ______________________ amounts, _____________ dissolving • We are familiar w/ __________________ but doesn’t have to be Solution Equilibrium Dissolution (dissolves) – ______________ breaks apart (into ____________________________) (re-)crystallize - when dissolved __________________ comes ________ of soln (forms a __________) Solution Equilibrium – when the _______________ of these processes are ________________ © 2024 S. Gulde. Reproducing and distributing this material is prohibited. 2 CHE-102 Lecture Outline Chapter 13 Types of Solutions Terms for when a: _______________ or _______________ dissolve in a ________________ 1. Saturated solutions – Soln is in __________________________ w/undissolved solute What this means: contains ___________ amount of solute for a solvent, at a specific temp Sugar: 25°C = 211g/100g H2O 50 °C = 260g/100g H2O If add more solute it _____________ dissolve SOLUBILITY – amount of _______________________ needed to form a saturated solution The solubility of sugar at 25°C is _________________ 2. Unsaturated solutions – contains _____________ than max amount of solute, at a specific temp If add more solute it _____________ dissolve, until reach __________________________ 3. Supersaturated solutions – contains _____________ than the max amount of solute, at a specific temp To make: _____________ saturated solution, add _____________ then cool to original temp • _______g @ 25°C • Heat to ________ • Add until _____________g dissolved • Cool to ___________ • Not _______________ If add more solute seed crystal”, excess _______________________, until __________________________ reached (Alum exp. From CHE101) © 2024 S. Gulde. Reproducing and distributing this material is prohibited. 3 CHE-102 Lecture Outline Chapter 13 More Solution Terminology Terms for when a: _______________ mixes with a _____________ or __________ Miscible – mixes _________________________ Immiscible – _______________________ mix significantly Ex: Oil & Water WHY do Solutions form? 1. Entropy (∆S) – an increase in ________________________ (______________________________) 2. __________________ forces will ________________ each other “_______________________________________________”!! • Polar solvents dissolve: ____________________________ solutes • Nonpolar solvents dissolve: ________________________ solutes ______ solution b/c forces __________ similar © 2024 S. Gulde. Reproducing and distributing this material is prohibited. 4 CHE-102 Lecture Outline Chapter 13 Type of Forces: A. Intramolecular forces: forces b/t atoms _______________________ molecule (aka _______________! ________________ lines) Ionic, Covalent, Metallic B. Intermolecular forces (IMF): is b/t atoms ____________________________ molecules (____________ lines) London dispersion, Dipole-Dipole, H-bonding, Ion-dipole ______molecular force __________molecular force © 2024 S. Gulde. Reproducing and distributing this material is prohibited. 5 CHE-102 Lecture Outline Chapter 13 Intermolecular Forces (IMF) 1. London Dispersion forces–movement of electrons w/in the electron cloud creating an ____________________________ dipole (_____________________________ partial charge) Dipole – distribution of electrons, one end has electron excess (______), the other electron deficient (______) Can ___________________________ to _________dipole at any time Present between _____________ molecules London Forces Increase with: a) increasing _________________________ (more ______________________ to distort) b) _____________________________ shapes (more _____________________________) 2. Dipole-Dipole– attraction between neutral ______________________ molecules __________________________ dipole ( ) __________________ than London 3. Hydrogen bonding – ________________ strong ___________________________ force Requires: a) H atom bonded to ___________________ that is attracted to b) lone pair of another __________________________ atom 4. Ion-dipole − between ions & partial charges (________________________) of ________________________ molecules Exist when _________________ compounds (ex. NaCl) ________________ in polar substance (ex. water) © 2024 S. Gulde. Reproducing and distributing this material is prohibited. 6 CHE-102 Lecture Outline Chapter 13 Sample: CH3Cl & H2O 1. List all the intermolecular forces associated with: a) CH3Cl: (chloromethane) b) H2O: • Dispersion? • Dispersion? • Dipole-dipole? • Dipole-dipole? • H-bonding? • H-bonding? • Ion-dipole? • Ion-dipole? 2. List all the IMFs between CH3Cl & H2O: Dispersion? Dipole-dipole? H-bonding? Ion-dipole? 3. Will a solution of CH3Cl and H2O form, are they miscible? © 2024 S. Gulde. Reproducing and distributing this material is prohibited. 7 CHE-102 Lecture Outline Chapter 13 HOW do Solutions form? __________________________________________ are broken & new ________________ created! SOLVATION – when solute (ions or molecules) is _____________________________________ in a specific way HYDRATION – special case of solvation b/c __________________ = solvent NaCl(s) in water Water _________________ Water _____________ to Nacl NaCl apart There are 3 interactions involved in solution formation & each has an _____________________ (∆H) change + − Ex: NaCl(s) → Na (aq) + Cl (aq) A. Solute−Solute interaction (∆Hsolute): must be ____________________ ____________________ energy, ________thermic (____) B. Solvent−Solvent interaction (∆Hsolvent): must be ____________________ ____________________ energy, ________thermic (____) C. Solute−Solvent interaction (∆Hmix): must be __________________ ____________________ energy, ________thermic (____) All 3 processes occur at the ______________________________ © 2024 S. Gulde. Reproducing and distributing this material is prohibited. 8 CHE-102 Lecture Outline Chapter 13 OVERALL enthalpy of Solution (∆Hsoln): _____________ all 3 processes ∆Hsoln can be endothermic (_____) or exothermic (______) Depends on size of __________ Solution formation is favored when ∆Hsoln is ___________thermic! Solute-Solvent particles are highly ______________________ to each other ___________ is large Why does the disfavored _________thermic solution form? (NH4NO3 ∆HSoln = +26kJ) ___________________, ∆S (_____________________) counteracts ______________ ∆HSoln value • If ∆Hsoln is very __________________, _____________ soln forms © 2024 S. Gulde. Reproducing and distributing this material is prohibited. 9 CHE-102 Lecture Outline Chapter 13 Solution Formation Review 1. Enthalpy (∆Hsoln): ____________________ (due to force interactions) Solutions usually form when ∆Hsoln ________________________ • Strong ___________________________________ interactions 2. Entropy (∆S): _________________________ Solutions usually form when ∆S ______________________________ • Helps compensate for ∆Hsoln ________________________________________ Sample: Soln Forces CH3Cl & H2O 1. What processes are involved when CH3Cl dissolves in water? Solute= Solvent= Question: Force Enthalpy Label the following processes as exothermic or endothermic: (a) Breaking solvent-solvent interactions to form separated particles (b) Forming solvent-solute interactions from separated particles (a) (b) A. Endothermic Endothermic B. Endothermic Exothermic C. Exothermic Endothermic D. Exothermic Exothermic Question: Force Enthalpy From weakest to strongest, rank the following solutions in terms of Solvent–Solute interactions: NaCl in water, butane (C4H10) in benzene (C6H6), water in ethanol (C2H5OH) A. NaCl in water < C4H10 in C6H6 < water in ethanol B. Water in ethanol < NaCl in water < C4H10 in C6H6 C. C4H10 in C6H6 < water in ethanol < NaCl in water D. C4H10 in C6H6 < NaCl in water < water in ethanol © 2024 S. Gulde. Reproducing and distributing this material is prohibited. 10 CHE-102 Lecture Outline Chapter 13 Concentration of Solutions Qualitatively: _______________________ term Insoluble slightly soluble soluble very soluble ________/100gH2O ________/100gH2O Dilute vs. concentrated • The _______________ solute you have the ____________ concentrated the soln Quantitatively: _______________________________ calculated Concentration Units 1. Mass percent: Unit = ______________ ____________________________ b/c also referred to as mass of the component in exactly 100g soln • 7.2% by mass = 2. Mole fraction, X: moles of A Unit = _______________ ΧA = total moles of all components ________________________ indicates the component of interest 3. Molarity, M (molar soln): moles of solute Unit = __________ M= L of soln Most ________________ used ____________ to measure volume, but it changes with _________________ 4. molality, m (molal soln): Unit = ___________ ____________________________ of temp m= moles of solute kg of solvent Must know _____________________ of soln to convert b/t M & m. Memorize water density= __________________________________ © 2024 S. Gulde. Reproducing and distributing this material is prohibited. 11 CHE-102 Lecture Outline Chapter 13 Sample: Glycerol in Ethanol 1. Express the concentration of 50.0g glycerol (C3H8O3) in 60.0g of ethanol (C2H6O) if the density of the solution is 1.10 g/mL, in a) %mass b) mole fraction c) molality & d) molarity. Assume interested in ______________, unless specified a) % mass: b) mole fraction: c) molality: d) Molarity: © 2024 S. Gulde. Reproducing and distributing this material is prohibited. 12 CHE-102 Lecture Outline Chapter 13 Sample: mass NaCl 2. If you have a 3.30% by mass NaCl solution, calculate the mass of NaCl in a 46.6g saline solution. Sample: X NaCl 3. If you have a 33% by mass NaCl solution, calculate the mole fraction of NaCl. © 2024 S. Gulde. Reproducing and distributing this material is prohibited. 13 CHE-102 Lecture Outline Chapter 13 Lecture Summary: 1. Mass Relations 2. Mole Fraction 3. Molarity, M 4. molality, m Group: Glucose & H2O What is the m & M concentration of a solution that has 49.8g glucose (C6H12O6) dissolved in 100.0kg of water? NOTE: If water is solvent: M & m are ~ ________________ for _____________ solns • Ex: 49.8g glucose (C6H12O6) in 100.0kg of water (previous problem) Because: • 1 kg ______________________ ~ 1 kg __________________________ • 1 L ______________________ ~ 1 L __________________________ So, the density of water can also be written ___________________________ © 2024 S. Gulde. Reproducing and distributing this material is prohibited. 14 CHE-102 Lecture Outline Chapter 13 Sample: m & X Calculate the molality of methanol, CH3OH in water which methanol has a mol fraction of 0.133. © 2024 S. Gulde. Reproducing and distributing this material is prohibited. 15 CHE-102 Lecture Outline Chapter 13 Factors Affecting Solubility (of solutes in water) 1. Structural Factors: Like Dissolves Like a) Polarity: Solute solubility increases as _________________________________ increases • b/c more _______________________________ _________________ dissolved better b) Liquids: Solute solubility decreases as __________________________________________ increases • b/c solute becomes _____________________________________ • Hexanol & Ethanol are both ___________________, but hexanol is ______________ c) Gases: main force is _________________ thus solubility _____________________ with: • Increased _____________ • Increased ______________________ Question: Vitamin Which is more likely to be a water-soluble vitamin? A. Vitamin A B. Vitamin C C. They have the same solubility © 2024 S. Gulde. Reproducing and distributing this material is prohibited. 16 CHE-102 Lecture Outline Chapter 13 2. Pressure: Strongly affects dissolved _________________, but __________ solids or liquids ____________ solubility increases as the partial pressure of the ______________________ the solvent increases • Increased pressure results in __________________________________ w/liquid surface, thus more ___________________________________ by solvent Henry’s Law: M = Solubility of gas (____________________) P = Partial pressure of gas above solution (________) k = Henry’s law constant (____________) (varies w/temp & solute-solvent pair) Calculate the concentration of CO2 in a soft drink that is bottled with a partial pressure of CO2 of 4.0atm over the liquid at 25°C. The Henry’s law constant for CO2 in water at this temp is 3.4x10-2 mol/L⋅atm. © 2024 S. Gulde. Reproducing and distributing this material is prohibited. 17 CHE-102 Lecture Outline Chapter 13 3. Temperature: Depends on ________________: As temperature increases: a) Solubility of most SOLID solutes in water ________________ (Solute=______________, Solvent==______________) - b/c ______________ moves faster, able to form more _______________________________________ forces b) Solubility of most GAS solutes in water ________________ (Solute=______________, Solvent==______________) - b/c ___________ moves faster, more particles able to ___________ solvent Question: Most Miscible Which compound below is the MOST miscible with water? A. CH3OH B. CH3CH2OH C. CH3CH2CH2OH D. CH3CH2CH2CH2OH E. They all dissolve the same Question: Gas Solubility In general, as the temperature of a solution increases, the solubility of a gas solute A. increases B. decreases C. remains unchanged Lecture Summary: Factors Affecting Solute Solubility in H2O: 1. Structure: a) Polarity: Solubility ______ w/_______ polarity b) Liquids: Solubility ______ w/________ carbon chain length c) Gases: Solubility _______ w/_________ Mm & in polarity 2. Pressure: Affects _________ solutes, ________ liquids or solids a) GAS solubility __________ w/__________ gas partial pressure b) Henry’s Law: 3. Temperature: affects __________ of solute differently. If Temp increases… a) Solid: solubility _______ b) Gas: solubility _______ © 2024 S. Gulde. Reproducing and distributing this material is prohibited. 18 CHE-102 Lecture Outline Chapter 13 Colligative Properties Colligative property – depends on ____________________ but not the kind of particles (_____________________ important) 1. Vapor Pressure lowering 2. Boiling point elevation 3. Freezing point depression 4. Osmotic pressure van’t Hoff factor, i: compensates for ___________________________________ dissolved Must consider what the _______________________ breaks up into? Non-Electrolytes: dissolve as entire ________________________________ • _______________________________ compounds, ex: Glucose: • Estimated i = _________ Typically ____________________________, but can be calculated C6H12O6(s) water → Strong Electrolytes: dissolve____________ into many ________________ • ___________________, Strong Acid or Strong Base • Estimated i = _____________________ FeCl3(s) → water Why is the calculated van’t Hoff factor (i) less than the estimated for _____________ compounds? Cations & anions can ____________________________ forming an ionic cluster (aka an ___________________) which act as a __________________ particle • Resulting in solute particle concentration being ______________________ the estimated number Ion pairing occurs ________________ as concentration of solute _____________________ Ex: NaCl: FeCl3: Estimated= 2 _____ Actual= 1.9 3.4 • © 2024 S. Gulde. Reproducing and distributing this material is prohibited. 19 CHE-102 Lecture Outline Chapter 13 Question: Largest van’t Hoff Which of the following has the largest van’t Hoff factor? A. 1.00m Ethanol (CH3CH2OH) B. 3.00m Glucose (C6H12O6) C. 0.60m CaCl2 D. 0.50m K2SO4 E. 0.50m Fe2(SO4)3 Vaporization of PURE Liquid Vaporization – lose _________ moving molecules (__________) Closed container: molecules trapped • ____________ liquid converted to a gas • ____________ gas converted to a liquid - Reversible Establishes Equilibrium • Equilibrium - when 2 reversible processes occur at the same rate Vaporization/Condensation rates are ________________ Molecular level: molecules ___________________________ entering & leaving liquid surface • Amount of gas present is _________________________ - ___ always in gas - ___ always in liquid © 2024 S. Gulde. Reproducing and distributing this material is prohibited. 20 CHE-102 Lecture Outline Chapter 13 Vapor Pressure Vapor pressure, (VP) – pressure exerted by a ___________ on a ___________ at equilibrium A ______________ vapor pressure means ________________________ molecules present Vapor Pressure LOWERING Terms to describe a SOLUTE Volatile – ______________ evaporates, ____________ Vapor Pressure (acetone) Nonvolatile – ______________ evaporates, ____________ Vapor Pressure (glycerin) Adding a _____________________________ solute to a solvent ALWAYS ___________________ the vapor pressure of the SOLUTION ___________ b/t solvent & solute cause the ___________________ to be _____________ stable in the liquid state • _______________ solvent _______ particles produced _______________ solute, the _______________ the SOLUTION VP © 2024 S. Gulde. Reproducing and distributing this material is prohibited. 21 CHE-102 Lecture Outline Chapter 13 Raoult’s Law: ___________ solutions obey Raoult’s Law: Solute conc. is _____________ Solute & solvent have similar ____________ & ______________ Psoln = VP of soln (w/___________________________ solute) XSolvent = mole fraction ( ° Psoln = (X solvent ) Psolvent ) P°solvent = VP of __________________ solvent nsolute = mols __________________________ dissolved Example: Which will lower the VP more when dissolved in water? A. 3.0 mol NaCl(s) B. 2.0 mol AlCl3(s) How many moles of solute would 3.0 moles of NaCl have? How many moles of solute would 2.0 moles of AlCl3 have? © 2024 S. Gulde. Reproducing and distributing this material is prohibited. 22 CHE-102 Lecture Outline Chapter 13 Sample: Psoln NaCl & AlCl3 Assume a pure solvent has the following Vapor Pressure (P°solvent) & mole amounts (nsolvent), what is the Psoln when NaCl &AlCl3 are added? P°solvent = 14.0 atm nsolvent = 6.0 mols Psoln = ? Adding nonvolatile solute ____________________ the VP of the SOLUTION _________ solute particles __________ VP more Vapor Pressure Lowering Can calculate the amount a solvent’s VP is _______________________: Calculate the Vapor Pressure Lowering for NaCl & AlCl3 in the previous problems. • NaCl: ∆P = 14.0atm – ______________ = ______________ • AlCl3: ∆P = 14.0atm – ______________ = ______________ © 2024 S. Gulde. Reproducing and distributing this material is prohibited. 23 CHE-102 Lecture Outline Chapter 13 Boiling & Freezing Points Phase diagram of Vapor Pressure Curves of a Pure Solvent (Black curve) Normal Boiling point – temp when liquid VP equals ____________ pressure (__________) Freezing point – temp when crystals of ________________________ form (___________) • ________________________ Add nonvolatile solute, Vapor Pressure is ________________________! Blue line=Solution (Pure Solvent = Black curve) What happens to: Normal Boiling point – ________________ temp needed to reach 1atm • Temp _______________________! Freezing point – ____________________________ temp needed to form crystals of solvent • Temp _______________________________! Boiling point ______________________ Freezing point ______________________ ∆Tb = (i)(Kb)(m) ∆Tf = (i)(Kf)(m) © 2024 S. Gulde. Reproducing and distributing this material is prohibited. 24 CHE-102 Lecture Outline i = van’t Hoff factor (# ___________________________________) m = ___________________________ (mol _______________/kg_______________) ∆T (of ______________________) = always __________________ Chapter 13 ∆Tb = _______________________ ∆Tf = _______________________ Kb = Solvent molal boiling point elevation constant Kf = Solvent molal freezing point depression constant Memorize H2O Temps Sample: MgCl2 1. Calculate the change in boiling point (in °C) when a solution of 275g of MgCl2 is added to 2.0kg of water. The Kb of water is 0.51°C/m © 2024 S. Gulde. Reproducing and distributing this material is prohibited. 25 CHE-102 Lecture Outline Chapter 13 Sample: Ethylene glycol 2. Ethylene glycol [EG, CH2(OH)CH2(OH)] is a common car antifreeze. It is water soluble and is a nonvolatile nonelectrolyte (bp=197°C, d=1.11kg/L). Calculate the freezing point of a 30.0% (by volume) solution. 3. The boiling point of pure ethanol (C2H5OH) is 78.4°C & it has a boiling point elevation constant of 1.22°C/m. If 38.96g of pentanol (a non-electrolyte) are added to 200.0g of ethanol to produce a solution boiling temp of 81.1°C, what is the molar mass of pentanol? © 2024 S. Gulde. Reproducing and distributing this material is prohibited. 26 CHE-102 Lecture Outline Chapter 13 Osmosis Osmosis – net movement of ____________________ molecules across a semipermeable membrane Semipermeable membrane – allows passage of certain _______________ molecules (water) but not large solute (molecules or ions) due to _______________________________ Movement always occurs from less ______________________ (____________________) → more ________________________ (______________________________) As if to _____________________ the concentrations • Note: Bio uses high solvent → low solvent As solvent moves, liquid levels become __________________ resulting in different __________________________ on each end of the tube Osmotic pressure (π) – pressure required to ____________ osmosis Similar to ____________________________ law n π = i RT = (i )(M )(R )(T ) V π = Osmotic pressure (______) i = _______________ particles in solution V = volume (_______) R = ideal gas constant (0.08206 L⋅atm/mol⋅K) T = temperature (_____) M = __________________ of particles (molecules or ions) © 2024 S. Gulde. Reproducing and distributing this material is prohibited. 27 CHE-102 Lecture Outline Chapter 13 Osmosis Terms A. Isotonic: soln of ____________________ concentration Solvent flow into cell ________________________ by flow out • Cell size ___________________________ B. Hypertonic – soln of ______________ concentration If place red blood cells in Hypertonic soln: • Crenation – water _______________ the cell − Cell size _______________________________ C. Hypotonic – soln of __________________ concentration If place red blood cells in Hypotonic soln: • Hemolysis – water _________________ the cell − Cell ______________________________ Sample: Highest Freezing 1. Which of the following aqueous solutions will have the highest and lowest freezing point? A. Pure water B. 0.10m sucrose (C12H22O11) C. 0.10m NaCl D. 0.10m Na2SO4 Question: Highest Boiling Which of the previous aqueous solutions will have the highest boiling point? A. B. C. D. Pure water 0.10m sucrose (C12H22O11) 0.10m NaCl 0.10m Na2SO4 © 2024 S. Gulde. Reproducing and distributing this material is prohibited. 28 CHE-102 Lecture Outline Chapter 13 Group: Hemoglobin A solution is prepared by dissolving 50.0g of hemoglobin, in enough water to make 500.0mL of solution. The osmotic pressure of the solution is measured & found to be 28.6mmHg at 25°C. Calculate the molar mass of hemoglobin (assume no change in volume when hemoglobin is added to water). © 2024 S. Gulde. Reproducing and distributing this material is prohibited. 29 CHE-102 Lecture Outline Chapter 13 Solutions Summary Solution formation Entropy – increased disorder Enthalpy – favorable intermolecular interactions • Intermolecular forces of solute-solute, solvent-solvent & solute-solvent Solubility 1. Influence of pressure – Henry’s Law 2. Influence of molecular structure – “like dissolves like” • Factors affecting solubility in water 3. Influence of temperature Concentration 1. Mass %, ppm, ppb 2. Mole fraction 3. Molarity 4. Molality Colligative properties van’t Hoff factor, i 1. Vapor Pressure – Raoult’s Law 2. Boiling pt. elevation 3. Freezing pt. depression 4. Osmosis © 2024 S. Gulde. Reproducing and distributing this material is prohibited. 30