DOC PREVIEW
Wright CHM 1220 - Enthalpy of Solutions
Type Lecture Note
Pages 3

This preview shows page 1 out of 3 pages.

Save
View full document
View full document
Premium Document
Do you want full access? Go Premium and unlock all 3 pages.
Access to all documents
Download any document
Ad free experience
Premium Document
Do you want full access? Go Premium and unlock all 3 pages.
Access to all documents
Download any document
Ad free experience

Unformatted text preview:

CHM 1220 1st Edition Lecture 1 Outline of Last Lecture (Recap of CHM 1210 topics)1. Periodicity/Periodic Trends Ionization energy, electron affinity, electronegativityCharge of Cations/anions based upon group2. Naming & Polyatomic Ions (reference chpt. 4 pg 141)Recognize names and structure interchangeably3. Stoichiometric Calculations (reference chpt. 7 pg 266)Find/Use mole ratios from balanced chemical equationsLimiting reagent, percent yield, molar mass determination4. Intermolecular interactions (reference chpt. 6 pg 238)Hydrogen-bonding, dispersion forces, dipole-dipoleIonic vs. covalent bonding5. Oxidation-reduction chemistry (reference chpt. 8 pg 332)Determination of oxidation state of atomIdentify what is being oxidized/reduced and what the oxidizing/reducing agents are6. Electrolytes/Non-electrolytes (reference chpt. 8 pg 318)Identify strong/weak/non-electrolytesRecognize Brønsted-Lowry acids & bases7. Enthalpy (reference chpt. 9 pg 371)First Law of ThermodynamicsSystem, surroundings, universe and sign conventionsHess’s Law and other ways to calculate enthalpiesOutline of Current Lecture (Chapter 11 – Properties of Solutions):1. Enthalpy of solutions2. Lattice Energy3. Born-Haber Cyclea. Practice problem4. Calculation of U Current Lecture (Chapter 11 – Properties of Solutions):1. Enthalpy of Solution (pg. 465)i) Enthalpy of solutions occurs when solutes are dissolved in solvents.These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.∆Hsoln = ∆Hionic bonds + ∆Hdipole-dipole + ∆H ion-dipole2. Lattice Energy (U) (pg.466)i) Lattice energy forms its free ions in the gas phase and is the energy released from 1 mol of an ionic compound from its free ions in the gas phase. Crystal lattice is formedM+(g) + X-(g) → MX(s)*k = proportionality constant depending on lattice structure ∆Hsoln = ∆Hhydration + ∆Hionic bonds∆Hsoln = ∆Hhydration – U3. Born-Haber Cycle (pg.466)i) This is a series of steps to explain the formation of ionic solidsii) Steps with practice problemNa(s) + ½ Cl2(g) → NaCl(s) ∆Hf = -411.2 kJ(1) Sublimation of 1 mol Na(s) → Na(g)*This gives us ∆Hsub Hsub: Na(s) → Na(g)(2) Breaking bonds of ½ mol of Cl2(g)*This gives us ½ ∆HBE½Hbond energy: ½Cl2(g) → Cl(g) (3) Ionization of 1 mol Na(g) atoms*This gives us IE1 [ionization energy for the first element (Na)] HIE1: Na(g) → Na+(g) + e-(g)ExothermicEndothermicThis istheenergyrequired toremove ionsfromcrystallattice Key for Lattice Energy EquationQ1Charge of 1st ionQ2Charge of 2nd ionk* constantd Distance b/t 2 objects U=k⋅(Q1×Q2d)(4) Ionization of 1 mol Cl(g) atoms*This gives us EA1 HEA: Cl(g) + e-(g) → Cl-(g) (5) Formation of 1 mol NaCl(s) from ions(g)*Finally, this gives us U4. Calculation of U (lattice energy)i) Now that we have the information above in the red box, we can calculate the lattice energyii) Us the following equation to solve for UUNaCl = Hf - ½ HBE - HEA - Hsub - HIE1iii) Steps(1) Na+(g) + e-(g) → Na(g) -(HIE1) = -(495 kJ)(2) Cl-(g) → Cl(g) + e-(g) -(HEA) = -(-349 kJ)(3) Na(g) → Na(s) -(Hsub) = -(108 kJ)(4) Cl(g) → ½Cl2(g) -(½HBE) = -(½·242 kJ)(5) Na(s) + ½Cl2(g) → NaCl(s) Hf = -411 kJNa+(g) + Cl-(g) → NaCl(s)UNaCl = Hf - ½ HBE - HEA - Hsub - HIE1 = -786 kJU: Na+(g) + Cl-(g) →


View Full Document

Wright CHM 1220 - Enthalpy of Solutions

Type: Lecture Note
Pages: 3
Documents in this Course
Load more
Download Enthalpy of Solutions
Our administrator received your request to download this document. We will send you the file to your email shortly.
Loading Unlocking...
Login

Join to view Enthalpy of Solutions and access 3M+ class-specific study document.

or
We will never post anything without your permission.
Don't have an account?
Sign Up

Join to view Enthalpy of Solutions 2 2 and access 3M+ class-specific study document.

or

By creating an account you agree to our Privacy Policy and Terms Of Use

Already a member?