Qhov Tseem Ceeb Qhov txawv - Ionic vs Covalent Compounds
Ntau qhov sib txawv tuaj yeem raug sau tseg ntawm ionic thiab covalent compounds raws li lawv cov macroscopic zog xws li solubility hauv dej, hluav taws xob conductivity, melting point thiab boiling point. Qhov laj thawj tseem ceeb rau qhov sib txawv no yog qhov sib txawv ntawm lawv cov qauv kev sib raug zoo. Yog li ntawd, lawv cov qauv kev sib txuas tuaj yeem suav tias yog qhov sib txawv tseem ceeb ntawm ionic thiab covalent compounds. (Qhov txawv ntawm Ionic thiab Covalent Bonds) Thaum ionic bonds raug tsim, electron (s) yog pub los ntawm ib tug hlau thiab pub electron (s) tau txais los ntawm ib tug uas tsis yog-hlau. Lawv tsim ib tug muaj zog daim ntawv cog lus vim lub electrostatic attraction. Covalent bonds yog tsim los ntawm ob lub non-metals. Nyob rau hauv covalent bonding, ob los yog ntau tshaj atoms qhia electrons kom txaus siab rau txoj cai octet. Feem ntau, ionic bonds muaj zog dua covalent bonds. Qhov no ua rau muaj qhov sib txawv ntawm lawv lub cev.
Ionic Compounds yog dab tsi?
Ionic daim ntawv cog lus yog tsim thaum ob lub atoms muaj qhov sib txawv loj hauv lawv cov txiaj ntsig electronegativity. Nyob rau hauv tus txheej txheem ntawm kev tsim daim ntawv cog lus, qhov tsawg electronegative atom poob electron(s) thiab ntau electronegative atom tau txais cov electron(s). Yog li ntawd, cov txiaj ntsig tau raug them rov qab ions thiab lawv tsim ib daim ntawv cog lus vim muaj zog electrostatic attraction.
Ionic daim ntawv cog lus yog tsim los ntawm cov hlau thiab tsis yog hlau. Feem ntau, hlau tsis muaj ntau valence electrons nyob rau hauv lub plhaub sab nraud; Txawm li cas los xij, cov hlau tsis yog hlau muaj ze rau yim electrons hauv lub plhaub valence. Yog li ntawd, cov hlau tsis yog hlau yuav txais cov electrons kom ua tiav txoj cai octet.
Piv txwv ntawm ionic compound yog Na+ + Cl–à NaCl
Sodium (hlau) tsuas muaj ib qho valence electron thiab Chlorine (tsis yog hlau) muaj xya valence electrons.
Covalent Compounds yog dab tsi?
Covalent compounds yog tsim los ntawm kev sib koom electrons ntawm ob lossis ntau lub atoms kom txaus siab "octet txoj cai". Hom kev sib txuas no feem ntau pom muaj nyob rau hauv cov khoom siv tsis yog hlau, cov atoms ntawm tib lub ntsiab lus lossis cov ntsiab lus nyob ze ntawm lub rooj zaum. Ob lub atoms uas muaj ze li qhov zoo ib yam electronegativity tsis pauv (nyiaj / txais) electrons los ntawm lawv lub plhaub valence. Hloov chaw, lawv sib koom electrons kom ua tiav octet configuration.
Piv txwv ntawm covalent compounds yog Methane (CH 4), Carbon monoxide (CO), Iodine monobromide (IBr)
Covalent Bonding
Qhov txawv ntawm Ionic thiab Covalent Compounds yog dab tsi?
Kev txhais ntawm Ionic Compounds thiab Covalent Compounds
Ionic compound: Ionic compound yog tshuaj lom neeg ntawm cations thiab anions uas tau tuav ua ke los ntawm ionic bonds hauv cov qauv lattice.
Covalent compound: Covalent compound yog cov tshuaj sib txuas tsim los ntawm kev sib koom ntawm ib lossis ntau dua electrons, tshwj xeeb tshaj yog khub ntawm electrons, nruab nrab ntawm atoms.
Khoom ntawm Ionic thiab Covalent Compounds
Physical Properties
Ionic Compounds:
Tag nrho cov ionic compounds muaj nyob rau hauv cov khib nyiab ntawm chav tsev kub.
Ionic compounds muaj cov qauv siv lead ua ruaj khov. Yog li ntawd, lawv muaj cov ntsiab lus melting ntau dua thiab cov ntsiab lus boiling. Lub zog ntawm kev nyiam ntawm qhov zoo thiab qhov tsis zoo ions muaj zog heev.
| Ionic Compound | Zoo | Melting Point |
| NaCl - Sodium chloride | Dawb crystalline khoom | 801°C |
| KCl - Potassium chloride | dawb lossis tsis muaj xim vitreous crystal | 770°C |
| MgCl2– Magnesium chloride | dawb lossis xim tsis muaj xim crystalline khoom | 1412°C |
Covalent Compounds:
Covalent compounds muaj nyob rau hauv tag nrho peb hom; raws li cov khib nyiab, kua thiab roj hauv chav sov.
Lawv cov ntsiab lus melting thiab boiling yog qhov tsawg piv rau cov ionic compounds.
| Covalent Compound | Zoo | Melting Point |
| HCl-Hydrogen chloride | Ib xim tsis muaj roj | -114.2°C |
| CH4 -Methane | Ib xim tsis muaj roj | -182°C |
| CCl4 – Carbon tetrachloride | A dej tsis muaj kob | -23°C |
Kev coj ua
Ionic Compounds: Khoom ionic compounds tsis muaj electrons dawb; yog li ntawd, lawv tsis ua hluav taws xob hauv daim ntawv. Tab sis, thaum cov ionic compounds yaj nyob rau hauv dej, lawv ua ib tug tov uas ua hluav taws xob. Hauv lwm lo lus, aqueous daws ntawm ionic compounds yog cov hluav taws xob zoo.
Covalent Compounds: Tsis yog cov khoom sib xyaw ntshiab lossis cov ntawv yaj hauv dej tsis ua hluav taws xob. Yog li ntawd, covalent compounds yog cov khoom siv hluav taws xob tsis zoo hauv txhua theem.
Solubility
Ionic Compounds: Feem ntau ntawm cov ionic compounds yog soluble hauv dej, tab sis lawv yog insoluble nyob rau hauv non-polar solvents.
Covalent Compounds: Feem ntau ntawm cov khoom sib xyaw ua ke yog soluble hauv cov kuab tshuaj uas tsis yog-polar, tab sis tsis nyob hauv dej.
Hardness
Ionic Compounds: Ionic solids yog cov tawv tawv thiab nkig.
Covalent Compounds: Feem ntau, covalent compounds softer dua ionic solids.
Image Courtesy: "Covalent bond hydrogen" los ntawm Jacek FH - Tus kheej ua haujlwm. (CC BY-SA 3.0) ntawm Commons "IonicBondingRH11" los ntawm Rhannosh - Tus kheej ua haujlwm. (CC BY-SA 3.0) ntawm Wikimedia Commons
