CHEM 140A Chapter Notes - Chapter 6: Walks Plus Hits Per Inning Pitched, Methyl Group, Butane

• School: UCSD
• Department: Chemistry and Biochemistry
• Course: CHEM 140A
• Professor: Joseph M Oconnor

Document Summary

Ochem textbook notes chapter 6: properties and reactions of haloalkanes. Polarized c-h bond governs reactivity of substances. Must consider size of halogen substituent and polarity of c-h bond to see how they affect bond strength, bond length, molecular polarity, and boiling point. The c-x bond is polarized: halogens are more electronegative than carbon, electron density along c-x bond is displaced in direction of halogen, so x has partial negative charge and carbon has partial positive charge. Haloalkanes have higher boiling points than the corresponding alkanes: coulombic attraction between the partial charges; dipole-dipole interactions, boiling point increases with increasing size of x, because of greater ldf. Ldf arises from mutual correlation of electrons among molecules. Ldf stro(cid:374)gest (cid:449)he(cid:374) outer ele(cid:272)tro(cid:374)s are(cid:374)(cid:859)t held (cid:448)er(cid:455) tightl(cid:455) arou(cid:374)d (cid:374)u(cid:272)leus. More polarizable = stronger ldf = higher boiling point. Appli(cid:272)atio(cid:374)s a(cid:374)d hazards of haloalka(cid:374)es: (cid:862)gree(cid:374)er alter(cid:374)ati(cid:448)es(cid:863: fully halogenated liquid bromomethanes are effective fire retardants.