Isisabelo esikhawulelayo nephesenti lesivuno kuchaziwe

Kungani ama-mole, hhayi amagremu, enquma ukuthi yisiphi isisabelo esiphela

Isibalo esilinganisiwe sibala izinhlayiya. 2 H₂ + O₂ → 2 H₂O sisho ukuthi amamolekyuli amabili e-hydrogen asabela nemolekyuli eyodwa ye-oxygen, noma 2 mol no-1 mol. Asisho lutho ngqo ngamagremu, ngoba izinto ezahlukene zinezisindo ze-molar ezahlukene. Ngakho ukuqhathanisa izisindo zezisabelo ezimbili akukwazi ukukutshela ukuthi yisiphi esiphela kuqala.

Isilinganiso sama-mole esivela ezinombolweni ezandulelayo sisebenza njengesilinganiso sokushintshana phakathi kwezinto. Ukusisebenzisa, guqula isisindo noma ivolumu enikeziwe ngayinye ibe ama-mole kuqala, sebenzisa isilinganiso, bese ubuyela kumagremu kuphela uma umbuzo ubuza isisindo.

Isifaniso sasekhishini sikhombisa umqondo. Uma isamishi ngalinye lidinga izingcezu ezi-2 zesinkwa nengcezu e-1 yeshizi, izingcezu eziyi-10 zesinkwa nezi-7 zeshizi zenza amasamishi angu-5 kuphela. Isinkwa sikhawulela okuphumayo nakuba kunezingcezu eziningi zaso, ngoba iresiphi isisebenzisa ngokushesha okuphindwe kabili.

Izivivinyo ezimbili ezethembekile zesisabelo esikhawulelayo

Qhathanisa amanani omkhiqizo. Esisabelweni ngasinye, bala ukuthi singakha umkhiqizo omangakanani uma yonke into enye ingenamkhawulo. Isisabelo esinikeza inani elincane kakhulu lomkhiqizo siyakhawulela, futhi leli nani elincane kakhulu liyisivuno sethiyori. Lesi sivivinyo siphendula umbuzo ovame kakhulu olandelayo ngesikhathi esisodwa.

Qhathanisa okudingekayo nokukhona. Khetha isisabelo esisodwa, bala ukuthi sidinga isisabelo sesibili esingakanani, futhi uqhathanise nalokho okukhona. Uma kukhona okuncane kunalokho okudingekayo, isisabelo sesibili siyakhawulela; kungenjalo sokuqala. Indlela emfushane elinganayo ihlukanisa inani lesisabelo ngasinye ngama-mole ngenombolo yaso eyandulelayo; inani elincane kakhulu likhomba isisabelo esikhawulelayo.

Zombili izivivinyo zidinga isibalo esilinganisiwe namanani ngama-mole. Kuzisabelo ezintathu noma ngaphezulu, isivivinyo senani lomkhiqizo noma indlela emfushane yokuhlukanisa ngenombolo eyandulelayo ayiphutha kakhulu kunokuqhathanisa izisabelo ngamabhangqa.

Isibonelo esisebenzile: ucingo lwe-copper esixazululweni se-silver nitrate

I-copper idedela i-silver ku-silver nitrate: Cu(s) + 2 AgNO₃(aq) → Cu(NO₃)₂(aq) + 2 Ag(s). Ucezu lucingo lwe-copper olungu-3.00 g lufakwa esixazululweni esiqukethe u-8.50 g we-AgNO₃. Yisiphi isisabelo esikhawulelayo, yisiphi isisindo se-silver esingakheka, futhi sisala i-copper engakanani? Izisindo ze-molar zisebenzisa izisindo ze-athomu ezijwayelekile ze-IUPAC eziyiswe emadesimalini amabili (Cu 63.55, Ag 107.87, N 14.01, O 16.00), ngakho i-AgNO₃ ingu-169.88 g/mol.

Guqula ube ama-mole, uthatha izinombolo ezengeziwe: 3.00 g Cu ÷ 63.55 g/mol = 0.047207 mol Cu, no-8.50 g AgNO₃ ÷ 169.88 g/mol = 0.050035 mol AgNO₃. I-copper ibizodinga u-2 × 0.047207 = 0.094414 mol AgNO₃, kodwa kukhona u-0.050035 mol kuphela, ngakho i-AgNO₃ iyakhawulela, nakuba isisindo sayo cishe singaphindwe kathathu kwe-copper.

Isivuno sethiyori se-silver: 0.050035 mol AgNO₃ × (2 mol Ag / 2 mol AgNO₃) × 107.87 g/mol = 5.397 g, kubikwe njengo-5.40 g. Ukwenza ukubala kusekelwe ku-copper kuzobikezela u-10.18 g we-silver, ongakwazi ukwakheka ngoba i-silver nitrate iphela kuqala.

I-copper eweleyo: i-AgNO₃ idla u-0.050035 mol ÷ 2 = 0.025018 mol Cu, noma u-0.025018 mol × 63.55 g/mol = 1.590 g. I-copper esele = 3.00 g − 1.590 g = 1.41 g, kubikwe endaweni yekhulu ngoba u-3.00 g waziwa endaweni yekhulu. Isisindo siyongiwa: 5.397 g Ag + 4.693 g Cu(NO₃)₂ (187.57 g/mol) + 1.410 g Cu = 11.50 g, silingana no-3.00 g + 8.50 g ekuqaleni.

Isivuno sethiyori, sangempela nephesenti lesivuno

Isivuno sethiyori yilona nani eliphakeme lomkhiqizo isisabelo esikhawulelayo esingakwakha, kucatshangwa ukuthi ukusabela kuya ekupheleni njengoba kubhaliwe kungekho ukusabela okunye nokulahlekelwa. Isivuno sangempela yinani olihlukanisayo futhi ulilinganisa. Iphesenti lesivuno = (isivuno sangempela ÷ isivuno sethiyori) × 100%.

Izivuno ezingaphansi kuka-100% ziyajwayeleka. Ukusabela kungafinyelela ekulinganeni ngaphambi kokuba isisabelo esikhawulelayo siphele, ukusabela okungaphelele kuhlanganisa izinto okungadla izisabelo, futhi umkhiqizo uyalahleka ngesikhathi sokuhluza, sokudlulisa, sokuwasha noma se-recrystallization. Isivuno esingaphezu kuka-100% somkhiqizo okuthiwa mcwebile ngokuvamile sisho ukuthi usaqukethe isincibilikisi noma ukungcola, noma ukuthi isisindo sirekhodwe kabi. Sithathe njengophawu lokomisa nokukala kabusha, hhayi njengomphumela.

Izivuno zombili kufanele zichaze into efanayo ngamayunithi afanayo. Uma isivuno sethiyori sikuma-mole, guqula nesivuno sangempela sibe ama-mole, noma uvezé zombili ngamagremu.

Isibonelo esisebenzile: iphesenti lesivuno ekwakhiweni kwe-ester

I-isopentyl acetate, i-ester enephunga elifana nelebhanana, yakheka kusuka ku-acetic acid ne-isopentyl alcohol (3-methyl-1-butanol): C₂H₄O₂ + C₅H₁₂O → C₇H₁₄O₂ + H₂O. Ingxube engu-6.00 g we-acetic acid no-7.50 g we-isopentyl alcohol inikeza u-8.12 g we-ester ehlanzekile. Liyini iphesenti lesivuno?

Izisindo ze-molar (C 12.01, H 1.01, O 16.00): i-acetic acid 60.06 g/mol, i-isopentyl alcohol 88.17 g/mol, i-ester 130.21 g/mol. Amanani: 6.00 g ÷ 60.06 g/mol = 0.09990 mol ye-asidi no-7.50 g ÷ 88.17 g/mol = 0.08506 mol ye-alcohol. Isilinganiso singu-1:1, ngakho i-alcohol iyakhawulela futhi u-0.01484 mol we-asidi uweleyo. Ukusebenzisa isisabelo esisodwa ngokweqile kuyindlela evamile yokuphoqa ukusabela okukhawulelwa ukulingana okufana nalokhu ngakumkhiqizo.

Isivuno sethiyori = 0.08506 mol × 130.21 g/mol = 11.076 g. Iphesenti lesivuno = (8.12 g ÷ 11.076 g) × 100% = 73.3%, izinombolo ezibalulekile ezintathu zivela ku-8.12 g no-7.50 g. Ukuyisa isivuno sethiyori ku-11.1 g ngaphambi kokuhlukanisa bekuzonikeza u-73.2%, ngakho thatha inani elingayiswanga phambili.

Iphesenti lesivuno lisebenza futhi ngemuva. Ukuqoqa u-5.00 g we-ester ngephesenti lesivuno elifanayo elingu-73.3%, udinga isivuno sethiyori esingu-5.00 g ÷ 0.733 = 6.82 g, okungu-0.0524 mol we-ester. Lokho kudinga okungenani u-0.0524 mol, noma u-4.62 g, we-isopentyl alcohol, nge-asidi eweleyo.

Amaphutha esivuno nesisabelo esiweleyo okufanele uwahlole

Amaphutha amaningi kulezi zinkinga angamaphutha okusetha kunamaphutha ezibalo, ngakho ngamunye unokuhlola okungadingi ukuphinda ukubala konke.

Ngemuva kokuqeda, qinisekisa izinto ezintathu: isisabelo esikhawulelayo sakhethwa ngama-mole, isivuno sethiyori savela kulesosisabelo, futhi iphesenti lesivuno lingu-100% noma ngaphansi.

• Ukukhetha isisabelo esikhawulelayo ngokuqhathanisa izisindo. Esibonelweni se-copper, isisabelo esinesisindo esikhulu bekuyiso esikhawulelayo.
• Ukuqhathanisa amanani ngama-mole ngaphandle kwezinombolo ezandulelayo. Hlukanisa inani ngalinye ngenombolo yalo eyandulelayo, noma ubale umkhiqizo kusisabelo ngasinye.
• Ukubala isivuno sethiyori kusisabelo esiweleyo. Isivuno sethiyori siyilona elincane kakhulu lamanani omkhiqizo angaba khona.
• Ukuthola okweqile okusele ngokukhipha isisindo sento eyodwa kwesenye. Bala ukuthi isisabelo esiweleyo sidliwe kangakanani, emayunithini aso, bese ukhipha lokho ekuphelelweni kwento efanayo ekhona.
• Ukushintshanisa isivuno sangempela nesethiyori efomulini. Iphesenti lesivuno elingaphezu kuka-100% lomkhiqizo owomile, ohlanzekile lisho ukuthi kukhona okungalungile.
• Ukuyisa amanani aphakathi. Phinda isinyathelo sokugcina ngezinombolo ezingayiswanga ubone ukuthi izinombolo ezibikiwe ziyashintsha yini.