Ukusebenza ngeekhemikhali kunye neeplastiki
Kwixesha elidlulileyo ikhemistri yayithathwa ‘njengomlingo omnyama’, ngoxa namhlanje sidibana nayo kuyo yonke inyathelo, kuquka nasekhaya. Siyazi ukuba nge-‘Crni bik’ okanye ezinye izicoci singahlamba impahla ngokulula. Abaninzi bayazi ukuba i-tetraethyl lead yonyusa inani le-octane yepetroli. Kakade ke, olo lwazi alwenzi umntu abe yingcali yekhemistri. Ukuze sibe njalo kancinane, masiqhelane neziseko zekhemistri:
Into enokwahlulwa ibe zezinye izinto, ezineempawu ezahlukeneyo, ngeendlela ezilula zomzimba (ukukhetha, ukuhluza, umazibuthe njl.) ibizwa ngokuba ngumxube. Eyo, into efanayo ngokupheleleyo, engenako ukwahlulwa ngezo ndlela zilula ibe zizinto ezineempawu ezahlukeneyo ibizwa ngokuba yikhompawundi.
Iikhompawundi zakhiwe ziimolekyuli ezenziwe ziielementi, eziboshwe ngamabhondi athile amachiza. La mabhondi awavumeli ukuba ahlulwe lula. Ukutshatyalaliswa, ukuqhawuka kwaloo mabhondi kufuna amandla amakhulu, ungenelelo lwamachiza. Emva koko iimolekyuli ziqhekeka zibe ziiathom zezi elementi. Kudala kwakucingwa ukuba iiathom azinakuqhekeka ngakumbi. Kwinkulungwane yethu kuqinisekisiwe ingcinga yangaphambili yokuba iiathom zenziwe ngamasuntswana asisiseko amancinci ngakumbi, ahlukana omnye komnye kokubini ngobukhulu nangomthwalo wombane. Ezona ntsalela zisisiseko zinempendulo entle kakhulu zezi proton ehlelihlweyo, neutron engathathi hlangothi kunye ne-electron enegative.
Kuzo zonke iikhompawundi zii-92 izinto zendalo kuthatha inxaxheba kuphela i-15 ukuya kwi-20 izinto.
Ubunzima bee-athomu zeziqalelo sibulinganisa ngale ndlela, ngokuzithelekisa ukuba zinzima kangaphi kune-athomu yesona siqalelo silula sehydrogen (ngokweenkcazo ezintsha ukusuka kwi-1/12 ye-athomu yekhabhoni.
Akukho nanye kwezi zinto inokudibana nenye into ngamaxabiso angenamlinganiselo, naluphi na uhlobo. Ukukwazi kwendawo yehydrogen ukwenza ibhondi yekhemikhali sikuthatha njengento enye. Ngoko ke, i-athomu yehydrogen inivalence enye. I-athomu, ethi kunye ne-athomu enye yehydrogen yenze ikhompawundi nayo inivalence enye. Ukuba into ibopha ii-athomu ezimbini, ezintathu, ezine njl. zehydrogen ngoko ke yona inivalence ezimbini, ezintathu, ezine njl. Inivalence ezisibhozo lelona nqanaba liphezulu levalence elinokubakho kwento enye. Nangona kunjalo, kukho izinto ezinovalence ezininzi; ezo zezi ziguquguqukayo ngokwevalence.
Amaqela aphambili eemixube zizinto ezingaphiliyo nezinto eziphilayo. Kwiikhompawundi eziphilayo kukho ikhabhoni, kanti kwezingaqhelekanga - ngaphandle kwezimbalwa ezingaqhelekanga - ayikho ikhabhoni.
Isizathu sobukho benani elikhulu leekhompawundi eziphilayo sikufumaneka ekukwazini ukubotshelana kwee-athomu zekhabhoni, oko kukuthi, ekwenziweni kwamatyathanga ekhabhoni. (Igama elithi iikhompawundi eziphilayo livela kumbono wangaphambili wokuba zizinto eziphilayo kuphela ezinokuzivelisa.)
Iiasidi zizinto eziyingozi nezitshabalalisayo ezibangela amanxeba anzima eluswini okanye esiswini, afana nokutsha. Iiasidi zinokubonwa lula ngephepha le-litmus, kuba i-litmus eluhlaza iba bomvu xa ikwi-asidi. Xa kusetyenziswa iiasidi kuyimfuneko ukunxiba iigoggles zokhuselo kunye neeglavu zerabha. Ukuba, nangona kuqatshelwe ngononophelo, ithontsi leasidi liwe esikhumbeni sethu - kufuneka kuqala licoshwe ngelaphu elomileyo, emva koko lihlambwe phantsi kwamanzi ahambayo, yaye ekugqibeleni imikhondo yeasidi ingathathaleliswa ngesisombululo sesoda-bicarbonate (umzobo 1).
UMFANEKISO 1
IISISEKO ziimveliso zokuphendula zii-oxide zentsimbi namanzi. Ama-alkali ngamagama asetyenziswa kwiiseko ezinyibilikayo emanzini yaye ezine mpembelelo yokonakalisa. Ziyabonakala lula, kuba zenza ukuba ilitmasi ebomvu ijike ibe luhlaza okwesibhakabhaka. Zizinto ezonakalisa kakhulu. Amanxeba abangelwa zizo ayaphiliswa nzima, kunamandla ngakumbi kunamanxeba abangelwa ziiasidi. Imigaqo ye-HSE iyafana neyaseziasidini. Xa umntu wonzakele, ulusu kufuneka luhlanzwe ngeasidi exutyiweyo (umzekelo iasidi yeviniga).
IIITYE ziveliswa ngokusabela kweziseko neeasidi. Azikho okanye zitshephe kancinane kakhulu ulusu. Nangona kunjalo xa usebenza ngetyuwa kufuneka kuqatshelwe ngononophelo, kuba ezinye zinetyhefu.
Iikhemikhali ezisendlwini
Kudala kusaziwa oko, ingakumbi xa kugcinwa iimveliso zokutya.
Izixhobo zokulondoloza zingahlulwa zibe:
1. Izinto ezithi ngaxeshanye zinike incasa kwaye zigcine iimveliso: iswekile, ityuwa, iviniga, amanqatha, i-citric acid, i-tartaric acid.
2. Izinto zokutshabalalisa ii-microorganism: isalitra, i-asidi ye-glutamic, ialum, ubisi lwekalika, isalicyl, i-asidi ye-benzoic kunye nesodium benzoate.
3. Izinto ezinjengejeli, imibala nezinongo.
Iswekile. Ngokudibanisa 55% yeswekile (iswekile =C12H22O11) kwimveliso ethile (eyeeplamu, amaqunube, iiaprikoti, ipere, iiapile) ngaphandle kokongeza ezinye iikhemikhali siye sayigcina ngokupheleleyo (i-slatko). Akukhuthazwa ukongeza ngaphezu kwe55% yeswekile, kuba iswekile iya kucwebezela. Isixa esingaphantsi kwe50% yeswekile asigcini. Xa iswekile yongezwa kwiimveliso zokutya ezineasidi, kufuneka kubiliswe ixesha elifutshane kuphela, kuba iswekile iyabola.
Ityuwa. Ityuwa yasekhitshini (sodium chloride, NaCl) nayo inika incasa yaye kwangaxeshanye iyagcina. Amandla ayo okugcina avela ngenxa yokufunxa ukufuma kwetyuwa (i-hygroscopicity). Ukuba inyama ifakwa ityuwa, ityuwa ibopha umthamo othile wamanzi kungekuphela kwinyama kodwa nakwiibhaktheriya yaye ngaloo ndlela izitshabalalise. Ezinye iintsholongwane nazo azinakuphila ngaphandle kwamanzi.
I-salitra. (i-Potassium nitrate, KNO3). Umgubo omhlophe, onetyuwa, okrakra, oneekristale. Ayinamatyala. Ukugcina 2,5 kg inyama, siyanyibilikisa 0,5 gram ye-potassium nitrate kwi-100 g yamanzi ashushu. Inyama eqatywe yahluzwa siyinyakamisa ngesi sisombululo. Kufuneka kulandelwe idosi echanileyo, kuba ngobuninzi obukhulu i-potassium salitra ikrakra kakhulu kwaye inetyhefu.
I-asidi ye-glutamic (i-asidi ye-amino-pyruvic, i-asidi ye-amino-glutaric, НООС-СН2-СН2–СН(NH)2–СООН) yi-amino acid efumaneka phantse kuzo zonke iiprotheyini. Isetyenziswa ekwenziweni kweekhonsetreyithi zeesuphu ezahlukeneyo, iisuphu ezirhaxayo (Podravka, Knorr njl.), okanye ekugcinweni kwenyama. Ku 1 kg yenyama kuthathwa 5 g ye-asidi ye-glutamic enyibilikisiweyo.
I-alum (potassium–aluminium–sulfate, KAl(SO4)2 isetyenziswa ikwimo ecocekileyo ekugcineni, okanye ekomelezeni isakhiwo seziqhamo ezithambileyo, imifuno, ukuze ingachithakali, ingatshabalali ngexesha lokugcinwa. Ku 1 kg yeziqhamo, okanye imifuno, kusetyenziswa 1,4 g ye-alum.
Ubisi lwekalika. Lunefuthe elifanayo nesepha yomgubo we-alum. I0,5 kg yekalika ebhakathiweyo iyanyibilikiswa kwi5 yeelitha zamanzi size siyishiye ubusuku bonke, siyikhuphe ngononophelo ngokugalela (sithulule malunga ne2/3 sesisombululo esicacileyo) yaye kobu bisi bekalika [Ca(OH)2] simanzisa iziqhamo okanye imifuno de 15-20 minutu yaye ekugqibeleni siyihlambise ngamanzi ashushu.
Iasidi yelamuni. Iasidi yelamuni ixhaphake kakhulu ebukumkanini bezityalo. Ifumaneka phantse kuzo zonke iziqhamo (i-Oksi–propan–trikarbonska kiselina, C6H8O7) Iikristale ezingenavumba, ezingenambala zeasidi yelamuni zinyibilika emanzini ashushu. Kwi 1 kg yeziqhamo kuyafuneka 1 ukuya ku 2g yeasidi.
I-asidi yetartaric. Ayinambala, ayinavumba (C4H6O6), ityuwa yayo ye-potassium efumaneka kwiwayini. Isenzo sale asidi sifana nese-asidi yelamuni.
Iasidi ye-acetic. Ingenambala, inevumba elibukhali, into enobumuncu obukhulu etshisayo (СН3СООН). Lutshaba olukhulu lokungunda neebhaktheriya. Ngaphezu komthamo othile, kwindawo eneasidi, iibhaktheriya azikwazi ukuphila. Ngenxa yoko, iasidi ye-acetic isetyenziswa rhoqo kakhulu ekugcineni. Ezivenkileni ifumaneka kwiindawo ezahlukeneyo zokuxinanisa (amandla). Kwi 1 kg yemveliso ethile kwanele malunga ne 2-3 ye-desilitha yesisombululo 10%–s iasidi ye-acetic. Iasidi ye-acetic iyatshabalalisa inani elikhulu leentsimbi (intsimbi, ialuminiyam, ubhedu, izinki). Ikhompawundi eyenziwe yi-acetic acid kunye nobhedu okanye izinki inetyhefu, ngoko ke njengesikhongozeli se-asidi ye-acetic sinokusebenza kuphela isitya seglasi, se-ceramic, se-enamel, seplastiki okanye somthi.
Iasidi ye-salicylic ngumgubo omhlophe, onjengenaliti, wekristale, ongenavumba (C6H4(OH)COOH). Yityhefu ye-cell, yaye itshabalalisa iibhaktheriya neespore. Ngexabiso elikhulu inetyhefu nakumzimba womntu, ngoko ke ekugcineni isetyenziswa ngamanani amancinci, achaziweyo ngokuchanekileyo. Ku 1 kg yeziqhamo kongezwa ubuninzi be 0,8 g.
I-benzoic acid yinto emhlophe, ethambileyo, efana neenaliti okanye iipleyiti, ikristale (Н6С5СООН). Itshabalalisa iibhaktheriya kunye neespores kakuhle kakhulu. Kwimilinganiselo emikhulu ikwamonakalisa nomzimba, ngoko ke kwi1 kg yeemveliso kongezwa kuphela 0,5 eegram.
Iiglue
Inani elikhulu leziglu zokwenziwa liya lisanda ukoyisa imarike. Nangona kunjalo akufanele sisokolelwe ligama elithi »iglue yendalo yonke«. Ezi glu zilungile kodwa azikho yendalo yonke; kwizinto ezithile zinamathela kakuhle, kwezinye zinamathela kancinci.
Siza kukhankanya ezinye zeencamathiselo ezibalulekileyo, ezinokufumaneka kwimarike yasekhaya, kunye nenqaku lokuba zeziphi izinto ezinokuncamatheliswa kakuhle kakhulu ngazo ezi ncamatheliso.
Igilu, (eyethambo, eyolusu) isetyenziswa ukuncamathelisa iphepha, umthi, amalaphu, icalefana, kwakunye nokuncamathelisa ezi zinto esikhumbeni nakwiglasi.
Вenzol sisinyibilikisi se-polistirol, okanye iglu yayo. Ukongeza ekuncanyathiseni amaphepha e-polistirol omnye komnye, i-plexiglas, i-celluloid kunye ne-cellophane nazo zifakwa ngebenzol kwi-polistirol.
Amanzi eglasi asetyenziswa ekuncamatheliseni iglasi nezinto eziqinileyo, njengebakhelayithi ngeteksi, iphepha, iintsimbi, i-porcelain ne-ceramic, oko kukuthi, ezi zinto omnye komnye.
I-klorofom sisinyibilikisi, oko kukuthi, yincamatheliso ye-plexiglas. I-Pleksiglas inokuncanyathiselwa ngeklorofom kwiglasi, ikheramiki, iporcelain, ipolistiroli kunye ne-celluloid.
IBoropor incamathelisa irabha kwirabha, irabha kwisinyithi, isikhumba, iglasi, iporcelain, umthi, ilaphu. Kwakhona isikhumba kwisinyithi, kancinci kwiglasi nakumthi.
Iglu ye-Oho »jikelele« isetyenziswa ngempumelelo ekuncamathiseni iglasi, iporcelain, iinkuni, i-poliplast, izinyithi.
I-Risopren (irabha eyenziweyo) isetyenziswa ikakhulu ukuncamathisela irabha nolusu. Ikwacebiswa nasekunamathiseleni ilinoliyam, ipodoliti, iiplanga ze-vinaz, kunye neparke kwi-beton.
ISavanol isetyenziswa ukuncamathelisa isikhumba, irabha, i-ultrapas, ikhaphethi, ilaphu, umthi, isalônit kunye nentsimbi egqunyiweyo nge-zinc.
Neostik un »universal« glue. Ingasetyenziswa ekuncamathiseni izinto ezahlukeneyo; ulusu, iinkuni, irabha, amalaphu njl.
Drvofix sisincamathelisi somthi, iipleyiti zomthi (i-panel, iverica njl.) ye-styrofoam emthini, iipakethi zomgangatho weparquet kumazantsi omthi njl.
Teleol (neoprene). Incamathelisi yokuncamathelisa isikhumba, irabha, izinto zeplastiki, ilaphu, iinkuni, izigqubuthelo zomgangatho zePVC njl.
Krautoxin (Kunstsoff aus der Tube). Iglu enamacandelo amabini, apho la macandelo mabini aqala axutywe aze emva koko asetyenziswe zingekapheli iiyure ezisibhozo ezinesiqingatha. Ibopha isinyithi, ilitye, iglasi, i-porcelain, ii-poliplaste ezimelana nobushushu (bakelite) njl.
Iiglu ze-epoksi, ezifana ne: ARALDIT (Switzerland), ЕРON (Shell), EPILOX (Buna-werke), EPORESIT (Hungary), zifumaneka ngamaxesha athile kwimarike, ngohlobo lomgubo, ipasta, iintonga, ii-emulsion. Ziiglu ezibalaseleyo, ingakumbi ekudityaniseni isinyithi nesinyithi, okanye irabha, ulusu njl.
Desmodur, desmoden zizincamathelisi ze-polyurethane, zisetyenziswa xa kunanyathiselwa isinyithi nerabha, okanye isinyithi nesinyithi.