Cov txheej txheem:

Vim li cas ethyl cawv muaj qhov kub siab tshaj li methyl cawv?
Vim li cas ethyl cawv muaj qhov kub siab tshaj li methyl cawv?

Video: Vim li cas ethyl cawv muaj qhov kub siab tshaj li methyl cawv?

Video: Vim li cas ethyl cawv muaj qhov kub siab tshaj li methyl cawv?
Video: Peb yuav ua li cas thiaj kov yeej dab lub hwj chim? 2024, Kaum ib hlis
Anonim

Ethanol muaj qhov kub siab dua li Methanol . Yog li ntawd, lub zog ntau dua yuav tsum tau kov yeej cov kev sib cuam tshuam hauv lub cev, ua rau muaj qhov nce ntxiv boiling / yaj cov ntsiab lus.

Hauv qhov no, vim li cas ethyl cawv muaj qhov kub siab dua?

Vim tias hydrogen bonds feem ntau muaj zog ntau dua li lub sijhawm dipole zoo tib yam, ib pawg ntawm ethanol molecules yog ib qho nyuaj rau kev sib cais ntawm ib leeg tshaj ib pawg ntawm dimethyl ether molecules. Cov ethanol muaj ntau siab kub taw tes.

Tsis tas li ntawd, dab tsi cuam tshuam qhov kub ntawm cov cawv? Cov boiling point ntawm cawv kuj nce asthe ntev ntawm hydrocarbon saw nce . Yog vim li cas cawv muaj siab dua kub point tshaj alkanes yog vim lub zog ntawm intermolecular cawv yog hydrogenbonds, tsis zoo li alkanes nrog van der Waals rog ua lawv lub zog nruab nrab.

Raws li txoj cai, cov cawv twg muaj qhov kub siab tshaj plaws?

Yog tias ib tus xav txog cov ntsiab lus kub (hauv ° C) ntawm cov dej cawv thawj zaug, ib tus pom cov hauv qab no:

  • Methanol: 65.
  • ethanol:79 ua.
  • 1:97.
  • 1-Butanol: 117.
  • 1- PIB: 138.

Puas yog thawj lossis theem nrab cawv puas muaj cov ntsiab lus kub dua?

Hydroxyl pawg ntawm a thawj cawv yog ntau "exposed" tshaj nws yog nyob rau hauv ib cawv thib ob (uas yog flanked los ntawm ob pawg alkyl loj), yog li nws yuav zoo dua rau hydrogen daim ntawv cog lus nrog lwm yam cawv (qhov zoo sib xws rau theem nrab vs qib cawv ).

Pom zoo: