Zitsanzo za Mafunso Okhudza Ma Covalent Bonds
Pendauluan
Chigwirizano cha covalent ndi mtundu wa mgwirizano wa mankhwala womwe maatomu awiri amagawana ma elekitironi awiri kapena angapo kuti akwaniritse mawonekedwe okhazikika a elekitironi, monga mu mpweya wabwino. Chigwirizanochi nthawi zambiri chimachitika pakati pa maatomu osakhala achitsulo omwe ali ndi ma electronegativities ambiri ndipo sasiyana kwambiri. Kupanga chigwirizano cha covalent kumachita gawo lofunika kwambiri mu chemistry yachilengedwe komanso yopanda chilengedwe ndipo ndiye maziko a zinthu zambiri zomwe timakumana nazo tsiku lililonse. M'nkhaniyi, tikambirana zitsanzo zingapo zokhudzana ndi ma covalent bonds ndikupereka mayankho kuti atithandize kumvetsetsa bwino.
Mafunso ndi Kukambirana Zitsanzo
Funso 1
Dziwani mtundu ndi chiwerengero cha ma covalent bond omwe amapangidwa mu molekyulu ya H2O (madzi).
Kukambirana:
Molekyulu yamadzi imakhala ndi atomu imodzi ya okosijeni (O) ndi maatomu awiri a haidrojeni (H).
1. Kapangidwe ka Electron:
– Mpweya: 1s² 2s² 2p⁴ (ma elekitironi 8 onse)
– Haidrojeni: 1s¹ (elekitironi imodzi yonse)
Mpweya wa okosijeni umafunika ma elekitironi ena awiri kuti ukwaniritse kapangidwe ka octet (ma elekitironi 8 mu chipolopolo chake chakunja), pomwe atomu iliyonse ya haidrojeni imafuna elekitironi imodzi kuti ikwaniritse kapangidwe ka duplet (ma elekitironi awiri mu chipolopolo cha K).
2. Kupanga Ma Covalent Bonds:
– Atomu iliyonse ya haidrojeni imagawana elekitironi imodzi ndi atomu ya okosijeni.
– Mpweya umagawana ma elekitironi awiri ndi ma atomu awiri a haidrojeni, imodzi pa atomu iliyonse.
Motero, ma covalent bond awiri amapangidwa mu molekyulu ya H2O, imodzi pakati pa atomu ya okosijeni ndi atomu ya haidrojeni motsatana.
Funso 2
Lembani kapangidwe ka Lewis ka molekyulu ya methane (CH₄).
Kukambirana:
Methane ili ndi atomu imodzi ya kaboni (C) ndi ma atomu anayi a haidrojeni (H).
1. Kapangidwe ka Electron:
– Kaboni: 1s² 2s² 2p² (ma elekitironi onse 6)
– Haidrojeni: 1s¹ (elekitironi imodzi yonse)
Kaboni ili ndi ma electron anayi a valence (2s² 2p²), ndipo imafunika ma electron ena anayi kuti ifike pa octet imodzi.
2. Kupanga Ma Covalent Bonds:
– Atomu iliyonse ya haidrojeni imagawana elekitironi imodzi ndi atomu ya kaboni.
– Mpweya umagawana ma elekitironi anayi ndi ma atomu anayi a haidrojeni, imodzi pa atomu iliyonse.
Kapangidwe ka Lewis ka methane ndi motere:
``
H
|
H – C – H
|
H
``
Mpweya uli pakati ndi ma bond anayi a covalent ku maatomu anayi a haidrojeni.
Funso 3
Dziwani kapangidwe ka Lewis ndi mawonekedwe a molekyulu ya carbon dioxide (CO₂).
Kukambirana:
Mpweya wa kaboni umapangidwa ndi atomu imodzi ya kaboni (C) ndi maatomu awiri a okosijeni (O).
1. Kapangidwe ka Electron:
– Kaboni: 1s² 2s² 2p² (ma elekitironi onse 6)
– Mpweya: 1s² 2s² 2p⁴ (ma elekitironi 8 onse)
Mpweya uli ndi ma elekitironi anayi a valence, pomwe atomu iliyonse ya okosijeni ili ndi asanu ndi limodzi. Mpweya umafunika ma elekitironi ena anayi kuti ukhale ndi octet, pomwe atomu iliyonse ya okosijeni imafuna awiri ena.
2. Kupanga Ma Covalent Bonds:
– Mpweya umagawana ma elekitironi awiri ndi atomu iliyonse ya okosijeni.
– Ma bond awiri ogwirizana amapangidwa pakati pa Carbon ndi Oxygen iliyonse.
Kapangidwe ka Lewis ka CO₂ ndi motere:
``
O = C = O
``
Mawonekedwe a molekyulu ndi olunjika okhala ndi ngodya yolumikizana ya 180°.
Funso 4
Werengani chiwerengero chonse cha ma elekitironi a valence ndikujambula kapangidwe ka Lewis ka molekyulu ya ammonia (NH₃).
Kukambirana:
Ammonia imakhala ndi atomu imodzi ya nayitrogeni (N) ndi maatomu atatu a haidrojeni (H).
1. Kapangidwe ka Electron:
– Nayitrogeni: 1s² 2s² 2p³ (ma elekitironi 7 onse)
– Haidrojeni: 1s¹ (elekitironi imodzi yonse)
Nayitrogeni ili ndi ma electron asanu a valence, omwe amafunikira ma electron ena atatu kuti apange octet imodzi.
2. Chiwerengero Chonse cha Ma Electron a Valence:
– Nayitrogeni: ma elekitironi 5 a valensi.
– Haidrojeni (maatomu atatu): maelekitironi atatu (elekitironi imodzi pa atomu iliyonse).
Ma electron onse a valensi = 5 + 3 = ma electron 8 a valensi.
3. Kupanga Ma Covalent Bonds:
– Nayitrogeni imagawana elekitironi imodzi ndi atomu iliyonse ya haidrojeni.
Kapangidwe ka Lewis ka NH₃ ndi:
``
H
|
H – N – H
|
``
Ndipo ma elekitironi awiriawiri (awiriawiri) ali mu nayitrogeni.
Funso 5
Jambulani ndi kufotokoza kapangidwe ka Lewis ka nitrate ion (NO₃⁻).
Kukambirana:
Ioni ya nitrate ndi gulu la polyatomic lomwe lili ndi nayitrogeni imodzi (N) ndi ma oxygen atatu (O), ndi mphamvu yoipa.
1. Kapangidwe ka Electron:
– Nayitrogeni: 1s² 2s² 2p³ (ma elekitironi 7 onse)
– Mpweya: 1s² 2s² 2p⁴ (ma elekitironi 8 onse)
Nayitrogeni ili ndi ma elekitironi asanu a valence, pomwe mpweya uliwonse uli ndi ma elekitironi asanu ndi limodzi a valence.
2. Chiwerengero Chonse cha Ma Electron a Valence:
– Nayitrogeni: ma elekitironi 5.
– Mpweya (maatomu atatu): ma elekitironi 18 (ma elekitironi 6 pa atomu iliyonse).
– Zowonjezera chifukwa cha ma ayoni oipa: 1 electron.
Ma electron onse a valensi = 5 + 18 + 1 = ma electron 24 a valensi.
3. Kupanga Ma Covalent Bonds ndi Kukonzekera kwa Ma Structures a Lewis:
– Nayitrogeni imapanga mgwirizano wawiri ndi imodzi mwa maatomu a okosijeni ndipo imapanga mgwirizano umodzi ndi maatomu ena awiri a okosijeni.
- Kugawa kofanana kwa mphamvu yoipa pakati pa maatomu awiri a okosijeni okhala ndi ma bond amodzi kumakhudza kusinthasintha kwa mphamvu.
Kapangidwe ka Lewis ka NO₃⁻ ndi:
``
O
/
YAM'MBUYO = O
``
Koma chizindikiro cha resonance chiyenera kuwonjezeredwa kuti chifotokoze za delocalization ya ma electron.
Mapeto
Kugwirizana kwa covalent ndi lingaliro lofunikira mu chemistry, komwe maatomu amagawana ma elekitironi kuti akwaniritse kukhazikika. Kumvetsetsa momwe angajambule kapangidwe ka Lewis, kuwerengera ma elekitironi a valence, ndikupeza mawonekedwe a molekyulu ndi luso lofunikira kuti mumvetsetse bwino momwe mankhwala amagwirira ntchito. Kudzera mu zitsanzo zomwe zili pamwambapa, tikuyembekeza kuti owerenga amvetsetsa bwino kapangidwe ndi mawonekedwe a ma covalent bonds.
