Mibvunzo Yemuenzaniso Inotsanangura Maumbirwo Emamorekuru
Pengantar
Chemistry inyaya yekudzidza maitiro ezvinhu uye shanduko dzinoitika. Imwe pfungwa inokosha mukemistri ndeyekunzwisisa chimiro chemamorekuru. Chimiro chemamorekuru chinokanganisa hunhu hwemuviri nemakemikari emakomikari, senge poindi yekunyunguduka, poindi yekufashaira, uye kumanikidzwa kwemhepo. Chimiro chemamorekuru chinoitawo basa rakakosha mukuona maitiro emakemikari anoitika mumakomikari iwayo. Dzidziso inonyanya kushandiswa kutsanangura chimiro chemamorekuru idzidziso yeVSEPR (Valence Shell Electron Pair Repulsion). Muchinyorwa chino, tichakurukura mienzaniso yakati wandei yematambudziko ane chekuita nechimiro chemamorekuru uye kuti dzidziso yeVSEPR ingashandiswa sei kuzvigadzirisa.
Dzidziso yeVSEPR
Dzidziso yeVSEPR idzidziso inoshandiswa kuona chimiro chemamorekuru zvichibva pakudzoserwa kwemaerekitironi maviri akakomberedza atomu repakati. Zvichienderana nedzidziso iyi, maerekitironi maviri anozvironga nenzira yekuti kudzoserwa kuri pakati pawo kushoma. Izvi zvinoita kuti molekyuri itore chimiro chaicho, chinofanotaurwa. Maerekitironi maviri aya anosanganisira maerekitironi maviri anobatanidza (BEPs) uye maerekitironi maviri ega ega (LOPs).
Mamwe emhando dzemamorekuru anogadzirwa anowanzo kuve:
1. Mutsetse
2. Purani yeTrigonal
3. Tetrahedral
4. Trigonal Bipyramidal
5. Guta reOctahedral
6. Yakakombama (yakakombama)
7. Seesaw
8. Yakaumbwa neT
9. Purani Yesikweya
10. Piramidhi Yesikweya
Tevere, ngatitarisei mimwe mienzaniso yemibvunzo nehurukuro dzayo.
Muenzaniso Mubvunzo 1: Kuziva Chimiro cheMamorekuru eCH4
Mubvunzo:
Tsvaga chimiro chemamorekuru chemethane (CH4) uchishandisa dzidziso yeVSEPR.
Kukurukurirana:
1. Sarudza Maumbirwo aLewis:
– Atomu yepakati: C (kabhoni)
– Kabhoni ine maerekitironi mana evalensi.
– Hydrogen imwe neimwe ine electron imwe chete ye valence.
– Maerekitironi ese eValensi = 4 (C) + 4 x 1 (H) = maerekitironi masere eValensi.
Maumbirwo eC4 muLewis anoratidza kabhoni iri pakati ine maatomu mana ehydrogen anoumba zvisungo zvesigma (sigma) kune atomu yekabhoni. Hapana maerekitironi maviri ari oga paatomu yekabhoni.
2. Kuverenga Maerekitironi Maviri:
– PEI: Kune mabhondi mana, ese ari mabhondi emaerekitironi maviri.
– PEB: Hakuna maerekitironi maviri ari ega.
3. Kuziva Maumbirwo eMorekuru:
– Nehuwandu hwe4 PEI ne0 PEB, kugoverwa kwemaerekitironi akatenderedza atomu yepakati kuchatora chimiro chinoderedza kudzongonyedzwa.
- Chimiro chine kupararira kuri kure kwazvo ndiTetrahedral.
Saka, chimiro chemorekuru yeCH4 itetrahedral ine kona yechisungo inosvika madhigirii 109.5.
Muenzaniso Mubvunzo 2: Kuziva Chimiro cheMolecular cheNH3
Mubvunzo:
Tsvaga chimiro chemamorekuru cheammonia (NH3) uchishandisa dzidziso yeVSEPR.
Kukurukurirana:
1. Sarudza Maumbirwo aLewis:
– Atomu yepakati: N (nitrogen).
- Nitrogen ine maerekitironi mashanu evalence.
– Hydrogen imwe neimwe ine electron imwe chete ye valence.
– Maerekitironi ese evalensi = 5 (N) + 3 x 1 (H) = maerekitironi masere evalensi.
Maumbirwo eLewis eNH3 anoratidza nitrogen pakati nemaatomu matatu ehydrogen achigadzira zvisungo zvesigma (sigma) neatomu yenitrogen uye peya imwe chete yemaerekitironi panitrogen.
2. Kuverenga Maerekitironi Maviri:
– PEI: Kune mabhondi matatu, ese ari mabhondi emaerekitironi maviri.
– PEB: Pane electron peya imwe chete.
3. Kuziva Maumbirwo eMorekuru:
– Nehuwandu hwe3 PEI ne1 PEB, kugoverwa kwemaerekitironi akatenderedza atomu yepakati kuchatora chimiro chinoderedza kudzongonyedzwa.
- Chimiro chine kugoverwa kwakakodzera iTrigonal Pyramidal.
Saka, chimiro chemorekuru yeNH3 chine piramidhi nhatu ine kona yebond iri pasi pemadhigirii 109.5 nekuda kwekudzingwa nepeya remaerekitironi rimwe chete rakasimba.
Muenzaniso Mubvunzo 3: Kuziva Chimiro cheMorekuru dzeH2O
Mubvunzo:
Tsvaga chimiro chemorekuru yemvura (H2O) uchishandisa dzidziso yeVSEPR.
Kukurukurirana:
1. Sarudza Maumbirwo aLewis:
– Atomu yepakati: O (okisijeni).
– Okisijeni ine maerekitironi matanhatu evalence.
– Hydrogen imwe neimwe ine electron imwe chete ye valence.
– Maerekitironi ese eValensi = 6 (O) + 2 x 1 (H) = maerekitironi masere eValensi.
Maumbirwo eLewis eH2O anoratidza okisijeni iri pakati nemaatomu maviri ehydrogen achiumba zvisungo zvesigma neatomu yeokisijeni uye maerekitironi maviri ari oga ari paokisijeni.
2. Kuverenga Maerekitironi Maviri:
– PEI: Kune mabhondi matatu, ese ari mabhondi emaerekitironi maviri.
– PEB: Pane electron peya imwe chete.
3. Kuziva Maumbirwo eMorekuru:
– Nehuwandu hwe2 PEI ne2 PEB, kugoverwa kwemaerekitironi akatenderedza atomu yepakati kuchatora chimiro chinoderedza kudzongonyedzwa.
- Chimiro chine kugoverwa kwakakodzera ndiBent.
Saka, chimiro chemorekuru yeH2O chakakombama nekona yechisungo yeanenge madhigirii 104.5.
Muenzaniso Mubvunzo 4: Kuziva Chimiro cheMolecular chePCl5
Mubvunzo:
Tsvaga chimiro chemamorekuru chephosphorus pentachloride (PCl5) uchishandisa dzidziso yeVSEPR.
Kukurukurirana:
1. Sarudza Maumbirwo aLewis:
– Atomu yepakati: P (phosphorus).
- Phosphorus ine maerekitironi mashanu evalence.
– Chlorine imwe neimwe ine maerekitironi manomwe evalence.
– Maerekitironi ese eValensi = 5 (P) + 5 x 7 (Cl) = maerekitironi makumi mana eValensi.
Maumbirwo eLewis ePCl5 anoratidza phosphorus pakati nemaatomu mashanu echlorine achiumba mabhondi ega (sigma) neatomu yephosphorus. Hapana maerekitironi maviri ari ega paphosphorus.
2. Kuverenga Maerekitironi Maviri:
– PEI: Kune mabhondi matatu, ese ari mabhondi emaerekitironi maviri.
– PEB: Hakuna maerekitironi maviri ari ega.
3. Kuziva Maumbirwo eMorekuru:
– Nehuwandu hwe5 PEI ne0 PEB, kugoverwa kwemaerekitironi akatenderedza atomu yepakati kuchatora chimiro chinoderedza kudzongonyedzwa.
– Chimiro chine kugoverwa kwakakodzera iTrigonal Bipyramidal.
Saka, chimiro chemorekuru yePCl5 chine trigonal bipyramidal ine ma bond angle e90° ne120°.
Muenzaniso Mubvunzo 5: Kuziva Chimiro cheSF6 Molecules
Mubvunzo:
Tsvaga chimiro chemolecular chesulfur hexafluoride (SF6) uchishandisa dzidziso yeVSEPR.
Kukurukurirana:
1. Sarudza Maumbirwo aLewis:
– Atomu yepakati: S (sarufa).
– Sarufa ine maerekitironi matanhatu evalence.
- Fluorine imwe neimwe ine maerekitironi manomwe evalence.
– Maerekitironi ese evalensi = 6 (S) + 6 x 7 (F) = maerekitironi evalensi makumi mana nemasere.
Maumbirwo eLewis eSF6 anoratidza sarufa pakati nemaatomu matanhatu efluorine achiumba mabhondi ega (sigma) neatomu yesarufa. Hapana maerekitironi maviri ega pasarufa.
2. Kuverenga Maerekitironi Maviri:
– PEI: Kune mabhondi matatu, ese ari mabhondi emaerekitironi maviri.
– PEB: Hakuna maerekitironi maviri ari ega.
3. Kuziva Maumbirwo eMorekuru:
– Nehuwandu hwe6 PEI ne0 PEB, kugoverwa kwemaerekitironi akatenderedza atomu yepakati kuchatora chimiro chinoderedza kudzongonyedzwa.
– Chimiro chine kugoverwa kwakakodzera iOctahedral.
Saka, chimiro chemorekuru yeSF6 chine denderedzwa reoctahedral ine kona yebond ye90°.
Mhedziso
Kunzwisisa chimiro chemamorekuru ndicho chinhu chakakosha pakutsanangura zvakawanda zvemakemikari nemuviri zvemusanganiswa. Dzidziso yeVSEPR inopa nzira inoshanda yekufanotaura geometry yayo zvichibva pakuverenga kwekubatana uye mapeya ega ega. Mumuenzaniso wega wega wakurukurwa, maitiro acho anosanganisira kuona chimiro cheLewis, kuverenga mapeya emaerekitironi, uye pakupedzisira kuona chimiro chakakodzera chemorekuru. Nekudzidzira nguva dzose, chero ani zvake anogona kuva nehunyanzvi pakushandisa dzidziso yeVSEPR kuona chimiro chemamorekuru.
