AP Chemistry Intermolecular Forces and States of Matter

AP Chemistry Intermolecular Forces and States of Matter

AP Chemistry Intermolecular Forces and States of Matter Chemical properties are related only to chemical composition; physical properties are related to chemical composition AND the physical state of the substance at the time. O H2 intermolecular forces (IMFs): forces between molecules -- largely determine the physical properties of molecular liquids and solids covalent STRENGTH OF IMFs GASES < LIQUIDS < SOLIDS Solids w/highly-ordered

structures are crystalline. ionic and metallic Intermolecular Forces (IMFs) -- these are much weaker than ionic or covalent bonds (< 15% as strong) -- In vaporizing water, we overcome the IMFs between water molecules, NOT the bonds holding the but... molecule together. H Boiling (or freezing) doesnt affect these O H State of matter is determined by two opposing influences. If KE of

then the state particles is and IMFs are of matter is LOW MEDIUM HIGH Temp. affects KE STRONG MEDIUM WEAK solid liquid gas Pres. affects IMFs (proximity) -- BP and FP/MP depend on IMFs strong IMFs weak IMFs high BP, high MP/FP

low BP, low MP/FP When ions are present: ion-dipole forces For neutral molecules: dipole-dipole forces London dispersion forces hydrogen bonding forces electrostatic forces Types of IMFs There are different bonds between people: parent/child, boss/employee, friends, lovers, etc. Were not talking about bonds holding an individual together. Ion-Dipole Forces (IDFs)

-- exist between an ion and a partial charge on the end of a polar molecule (i.e., a dipole) -- important for... solutions of ionic substances in polar liquids e.g., aq. soln. of KCl Cl H H O KCl solution is given intravenously in cases of capital punishment by lethal injection. The KCl causes the heart muscle cells to cease contracting. IDF K+ momentary kissage Dipole-Dipole Forces (DDFs) -- exist between neutral polar molecules that are close together

-- weaker than IDFs -- as the dipole moment m (i.e., the polarity) increases... DDFs (thus, BP and MP ) Phosphine (PH3), is used in pest control fumigation due to its high toxicity. In the liquid phase, phosphine is subject to DDFs. London Dispersion Forces (LDFs) -- exist between all molecules, but are the ONLY forces between nonpolar molecules that are close together -- motion of e causes instantaneous dipoles, which induce dipoles on nearby mcules; LDFs with increasing molar mass -- polarizability: the ease with which the charge distribution in a molecule can be distorted by an external magnetic field -- large atoms w/lots of e exhibit

high polarizability Hydrogen Bonding Forces (HBFs) C N O F 2.5 -- strongest IMF; special class of DDF 3.0 3.5 4.0 P S Cl 2.1 2.5 3.0

Se Br -- exist between a hydrogen atom 2.4 2.8 in a polar bond and an unshared electron pair on a nearby, small, highly electronegative ion or atom (e.g., F, O, N, Cl) -- bare proton of H is attracted to unshared e pairs; its small size allows close proximity/strong bond -- important in structures of proteins and DNA HBFs act between water/ice molecules. Water expands 9% when it freezes. H O H H

O H H O O H H H H H H O O H

ice H H O H H H O O H water H

H O H H O O H H

Recently Viewed Presentations

  • Subcutaneous Mycoses - partial presentation

    Subcutaneous Mycoses - partial presentation

    Subcutaneous Mycoses Mycetoma (clincal syndrome of localized, indolent, deforming, swollen lesions and sinuses, involving cutaneous and subcutaneous tissues, fascia, and bone; usually occurring on the foot or hand) - etiologic agent may be bacterial or fungi.
  • Types of Jobs - EL Civics

    Types of Jobs - EL Civics

    Types of Jobs ESL Employment Lesson for Beginners Bank Teller Cook Carpenter Electrician Fire Fighter Librarian Pilot Waitress Welder Plumber Delivery Person The End Learn English at www.elcivics.com Types of Jobs ESL Employment Lesson for Beginners Bank Teller Cook Carpenter...
  • Catholicism Renaissance to Present Early Catholicism & the

    Catholicism Renaissance to Present Early Catholicism & the

    During and before WWI, Saint Pope Pius X made many reforms, including numerous communions and promoting Gregorian Chant in France. As the beginning of the 20th century brought WWI, Pope Benedict XV declared neutrality, but neither of the sides believed...
  • ACKNOWLEDGEMENT The RYA thank the publishers of the

    ACKNOWLEDGEMENT The RYA thank the publishers of the

    CHART DESCRIPTION. ENGLAND - SOUTH COAST. MANACLE POINT TO BOLT HEAD. DEPTHS IN METRES. SCALE 1:150,000 at Lat 50 00´ Depths are in metres and are reduced to Chart Datum, which is approximately the level of Lowest Astronomical Tide.
  • PharmaSim Case Preparation - Google Groups

    PharmaSim Case Preparation - Google Groups

    PharmaSim Case Preparation. ... B&B health care, Curall Pharmaceuticals, Discol Corporation and Ethik Incorporated. ... Although 18% (or $74.9M)'s promotional allowance contribute to the sales, the comparably high Cost of Goods Sold lead to unsatisfactory gross margin which requires the...
  • Christian Morality Social Justice and Chapter D Working

    Christian Morality Social Justice and Chapter D Working

    The authors and Saint Mary's Press staff have made every attempt to refer-encecurrent and valid sources, but we cannot guarantee the content of any source, and we are not responsible for any changes that may have occurred since our verification.
  • Ii. Le Fonctionnement De L&#x27;Union Europeenne

    Ii. Le Fonctionnement De L'Union Europeenne

    Elle veut faire prévaloir ses intérêts au plan mondial en termes: - économiques - de recherche - d'équipements militaires - et en termes d'unité politique Il a fallu attendre les réflexions issues des mouvements de résistance au totalitarisme, pendant la...
  • Persuasive Speaking

    Persuasive Speaking

    Today's Agenda. Vicky's Event Proposal Presentation. Russell Stover's Candies Discussion. Persuasive Speaking 101. Pop Quiz 2 Answers & What To Know From The Book: Chapter 14