Silitsiy

Silitsiy az jihati pahnshavi dar qishri zamin bad az oksi- gen (takhminan 27%) joyi duyumro ishgol mekunad. Silitsiy dar tabiat tanho bo namudi payvastagihoyash vomekhurad, ki az onho ok- sidi silitsiy (IV) §YU₂ (kremnezyom) va kaolinit A1₂O₃^.28YU₂^. 2N₂O beshtar pahn shudaast. Oksidi silitsiy (IV) qismi asosii reg va kaolinit qismi asosii tarkibi gil meboshad. Dar tabiat silikat – ortoklaz K₂O A1₂O₃^.6§YU₂ (shpati sahroi) khele farovon ast.

Dar qabati berunii atomi silitsiy ba monandi atomi karbon 4 elektron mavjud ast. Radiusi atomi silitsiy nisbat ba radiusi atomi karbon kalon buda, qarobatash ba elektron kam meboshad. Az in sabab, khosiyati gayrimetallii silitsiy nisbat ba khosiyati metalli bartari dorad. Dar payvastagihoyash 8^ bo darajai ok- sidshavii -4, 0, +2 va +4 shuda metavonad.

Silitsiy du shakli allotropi dorad: shakli buluri (krisstali) va amorfi. Kristallhoi silitsiy rangi siyohi khokistari doshta, ba jiloi metally monandi dorand. Panjarai kristaliash ba panjarai kristallii almos monand buda, sakht va murt meshavad. Silitsiy ba nimnoqilho taalluq dorad. Silitsiyi amorfi kho- kai jigari buda, sokhti on ba almos monandi dorad

Baroi hosil kardani silitsiyi kholis onro az tetrakhloridi silitsiy bo tasiri gidrogen yo rukh barqaror mekunand.

8^S1₄ + 2N₂ ——® 81 + 4NS1;

8KT + 2Hp —— 81 + 2HpS1₂.

Dar sharoiti laboratori silitsiyro bo tasiri omekhtai regi toza va khokai magniy, ruh yo alyuminiy ba dast meorand:

2Md + 8YU₂ ¹ ® 2MdO + 81;

2Tp + 8YU₂ —-—® 2TpO + 81

Az bayni galogenho silitsiyi amorfi dar harorati khona tanho ba ftor tasir mekunad:

81 + 2G₂ ® 811 <

Dar harorati baland atomi silitsiy faol gardida, ba di- gar galogenho va inchunin ba oksigen, nitrogen, gidrogen va metallhoi faol tasir mekunad.

2Md + 81 —^–® \’1d,8| (si- litsidi magniy). 8YU₂ sokhti panjarai atomii buluri (kris- talli) dorad. Oksidi silitsiy (IV) monandi polimer yak mole- kulai azimero ifoda mekunad, ki atomhoi silitsiy bo chor atomi oksigen dar qullahoi te- traedr payvast shudaand, ki dar navbati khud oksigen bo du ato- mi silitsiy payvast ast. YAne kristallhoi 8YU₂ az zanjiri sokhti tetraedri iborat ast, ki bo oksigen bayni khud payvast meshavand.

Formulai 8YU₂ sharti buda, dar asl formulai sokhti onro bo (8YU₂)_p ifoda namudan durust meboshad. Oksidi silitsiy (IV) oksidi kislotagi buda, angidri- di kislotai silikat meboshad, ammo ba ob tasir namekunad (ras- mi 52). Kislotaho (biduni kislotai ftorid) ba silitsiy tasir namekunand, vale ishqorho ba vay ba reaksiya dokhil meshavand:

81 + 2\aO11 + N₂O ® \a,8YU. + 2N₂$

Tarkibi kislotai silikatro shartan bo formulai N₂8YU₃ tas- vir mekunand. Dar asl tarkibi on murakkab buda, formulai umu- miash p8YU₂ . tN₂O ast.

Kislotai silikat qarib dar ob halnashavanda ast. Bo ob vay mahluli kolloidi hosil mekunad. Azbaski in kislota dar ob ama- lan halnashavanda ast, ionhoi gidrogen az molekulahoi on kanda nameshavand. Az in sabab kislotai silikat nisbat ba kislotai karbonat zaif ast:

№₂8YU₃+ 2SO₂+2N₂O ® 2\a11SO. + N₂8YU_z;

Kislotai silikat noustuvor buda, hangomi garm kardan tajziya meshavad:

N₂8YU₃ ¹ ® 8YU₂ +N₂O

Namakhoi kislotai silikatro silikatho menomand. Tarki- bi namakhoro dar namudi oksidho ifoda mekunand, misol si- likati kalsiy Sa8YU₃ – SaO ^. 8YU₂. Az silikatho tanho silikati metallhoi ishqori halshavanda meboshad, ki mahluli konsent- ronidai on shishai moe nomida meshavad.

Kislotai silikat dar natijai ba mahluli namaki on tasir kardani kislotai qavi hosil karda meshavad:

\a,8YU. + 2NS1 ® 2№S1 + N₂8YU_z;

Silikatho bo hamai kislotahoi qavi ba reaksiya dokhil shuda, kislotai silikatro, bo namudi qiyom (gel), hosil mekunand. In reaksiyai sifati baroi ioni silikat ba hisob meravad.

Silikathoi halshavanda dar mahluli obi gidroliz meshavand va dar in hol muhit ishqori megardad:

\a,8YU. +2NON ® 2\aO11 + N₂8YU_z;;

2\a⁺ + ^YU^^2- +2NON ® 2\a’+2O11 ^– + N₂8YU_z;;

8YU₃^2- + 2NON ® N₂8YU_z;+ 2ON ^–.

Istifodabary. Istifodabarii silitsiy dar rasmi 52 ovarda shudaast.

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