Iron Age - Part 3

Qhov tseeb qhov teeb meem hais txog tus naj npawb ib hlau ntawm peb kev vam meej thiab nws txoj kev sib raug zoo. Cov kev sim ua kom deb li deb tau pom tias qhov no yog ib qho kev nthuav dav rau kev tshawb fawb hauv tsev. Cov kev sim niaj hnub no yuav tsis muaj qhov nthuav tsawg thiab yuav tso cai rau koj los saib sib txawv ntawm qee yam ntawm chemistry.

Ib qho kev sim nyob rau hauv thawj ntu ntawm tsab xov xwm yog oxidation ntawm ib tug greenish precipitate ntawm hlau (II) hydroxide rau xim av hlau (III) hydroxide nrog ib tug tov ntawm H.₂O₂. Hydrogen peroxide decomposes nyob rau hauv kev cuam tshuam ntawm ntau yam, nrog rau cov hlau tebchaw (oxygen npuas tau pom nyob rau hauv qhov kev sim). Koj yuav siv cov nyhuv no los qhia ...

… Lub catalyst ua haujlwm li cas

tau kawg ceev cov tshuaj tiv thaiv, tab sis - nws tsim nyog nco ntsoov - tsuas yog qhov uas tuaj yeem tshwm sim hauv cov xwm txheej (txawm tias qee zaum qeeb heev, txawm tias tsis pom tseeb). Txawm li cas los xij, muaj ib nqe lus hais tias tus catalyst accelerates cov tshuaj tiv thaiv, tab sis tsis koom nrog nws. Hm... yog vim li cas ntxiv nws? Chemistry tsis yog khawv koob (qee zaum nws zoo li ntawd rau kuv, thiab "dub" rau khau raj), thiab nrog kev sim yooj yim koj yuav pom cov catalyst hauv kev nqis tes ua.

Ua ntej npaj koj txoj haujlwm. Koj yuav xav tau ib lub tais kom lub rooj los ntawm dej nyab, hnab looj tes tiv thaiv, thiab tsom iav los yog lub visor. Koj tab tom soj ntsuam nrog cov tshuaj tua kab mob: perhydrol (30% hydrogen peroxide tov H₂O₂) thiab kev daws ntawm hlau (III) chloride FeCl₃. Ua kom zoo, tshwj xeeb tshaj yog saib xyuas koj ob lub qhov muag: daim tawv nqaij ntawm tes hlawv nrog pehydrol regenerates, tab sis qhov muag tsis ua. (1).

2. Lub evaporator nyob rau sab laug tsuas muaj dej, nyob rau sab xis - dej nrog ntxiv ntawm perhydrol. Koj nchuav cov tshuaj hlau (III) chloride rau hauv ob qho tib si

3. Cov chav kawm ntawm cov tshuaj tiv thaiv, tom qab nws ua tiav, cov catalyst yog regenerated

Ncuav rau hauv lub porcelain evaporator thiab ntxiv ob zaug ntau npaum li dej (cov tshuaj tiv thaiv kuj tshwm sim nrog hydrogen peroxide, tab sis nyob rau hauv cov ntaub ntawv ntawm ib tug 3% tov, cov nyhuv yog tsis pom zoo). Koj tau txais kwv yees li 10% kev daws teeb meem ntawm H₂O₂ (kev lag luam perhydrol diluted 1: 2 nrog dej). Ncuav dej txaus rau hauv lub evaporator thib ob kom txhua lub nkoj muaj cov kua dej tib yam (qhov no yuav yog koj tus qauv siv). Tam sim no ntxiv 1-2 cm rau ob qho tib si steamers.³ 10% FeCl kua₃ thiab ua tib zoo saib xyuas qhov kev xeem dhau los (2).

Nyob rau hauv lub evaporator tswj, cov kua muaj xim daj vim hydrated Fe ions.³⁺. Ntawm qhov tod tes, muaj ntau yam tshwm sim nyob rau hauv lub nkoj nrog hydrogen peroxide: cov ntsiab lus tig xim av, cov roj tso tawm ntau heev, thiab cov kua hauv lub evaporator kub heev los yog boils. Qhov kawg ntawm cov tshuaj tiv thaiv yog cim los ntawm kev tso tseg ntawm cov roj evolution thiab ib qho kev hloov ntawm cov xim ntawm cov ntsiab lus mus rau daj, raws li nyob rau hauv lub tswj system (3). Koj tsuas yog ua tim khawv xwb Kev ua haujlwm catalytic converter, tab sis koj puas paub qhov kev hloov pauv tau tshwm sim hauv lub nkoj?

Cov xim xim av los ntawm cov ferrous compounds uas tsim los ntawm cov tshuaj tiv thaiv:

Cov roj uas hnyav dhau los ntawm cov evaporator yog, tau kawg, cov pa oxygen (koj tuaj yeem tshawb xyuas seb cov nplaim taws puas pib hlawv saum cov kua dej). Hauv cov kauj ruam tom ntej, cov pa tawm hauv cov tshuaj tiv thaiv saum toj no oxidizes Fe cations.²⁺:

Regenerated Fe ions³⁺ lawv rov koom nrog thawj cov tshuaj tiv thaiv. Cov txheej txheem xaus thaum tag nrho cov hydrogen peroxide tau siv lawm, uas koj yuav pom thaum cov xim daj rov qab mus rau cov ntsiab lus ntawm cov evaporator. Thaum koj muab ob sab ntawm thawj qhov sib npaug los ntawm ob thiab ntxiv nws sab mus rau qhov thib ob, thiab tom qab ntawd tshem tawm cov ntsiab lus ntawm cov lus sib txawv (raws li nyob rau hauv ib qho piv txwv lej), koj tau txais qhov sib npaug ntawm cov tshuaj tiv thaiv H.₂O₂. Thov nco ntsoov tias tsis muaj cov hlau ions hauv nws, tab sis txhawm rau qhia lawv lub luag haujlwm hauv kev hloov pauv, ntaus lawv saum toj saud:

Hydrogen peroxide kuj spontaneously decomposes raws li cov kab zauv saum toj no (pom tseeb tsis muaj hlau ions), tab sis cov txheej txheem no qeeb qeeb. Qhov sib ntxiv ntawm cov catalyst hloov cov tshuaj tiv thaiv mechanism rau ib qho yooj yim rau kev siv thiab yog li ntawd speeds li tag nrho cov hloov dua siab tshiab. Yog li vim li cas lub tswv yim hais tias cov catalyst tsis koom nrog cov tshuaj tiv thaiv? Tej zaum vim hais tias nws yog regenerated nyob rau hauv tus txheej txheem thiab tseem tsis hloov nyob rau hauv lub sib tov ntawm cov khoom (hauv kev sim, xim daj ntawm Fe (III) ions tshwm sim ua ntej thiab tom qab cov tshuaj tiv thaiv). Yog li ntawd nco ntsoov cov catalyst yog koom nrog hauv cov tshuaj tiv thaiv thiab yog qhov ua haujlwm.

Rau qhov teeb meem nrog X.₂O₂

4. Catalase decomposes hydrogen peroxide (tub rau sab laug), ntxiv cov tshuaj EDTA rhuav tshem cov enzyme (tub rau sab xis)

Enzymes kuj yog catalysts, tab sis lawv ua nyob rau hauv lub hlwb ntawm cov kab mob nyob. Xwm siv hlau ions nyob rau hauv lub active chaw ntawm enzymes, accelerating oxidation thiab txo cov tshuaj tiv thaiv. Qhov no yog vim hais tias twb tau hais me ntsis kev hloov pauv ntawm cov hlau valence (los ntawm II mus rau III thiab vice versa). Ib qho ntawm cov enzymes no yog catalase, uas tiv thaiv cov hlwb los ntawm cov khoom muaj kuab lom heev ntawm cellular oxygen transformations - hydrogen peroxide. Koj tuaj yeem tau txais catalase yooj yim los ntawm mashing qos yaj ywm thiab ntxiv dej rau cov qos yaj ywm mashed. Cia lub suspension mus rau hauv qab thiab muab pov tseg lub supernatant.

Ncuav 5 cm rau hauv lub raj kuaj.³ qos yaj ywm extract thiab ntxiv 1 cm³ hydrogen peroxide. Cov ntsiab lus yog foamy heev, nws tuaj yeem "tawm" ntawm lub raj xa dej, yog li sim nws ntawm lub tais. Catalase yog ib qho enzyme uas muaj txiaj ntsig zoo, ib qho molecule ntawm catalase tuaj yeem tawg mus txog ntau lab H molecules ib feeb.₂O₂.

Tom qab nchuav cov extract rau hauv lub raj thib ob, ntxiv 1-2 ml³ EDTA daws (sodium edetic acid) thiab cov ntsiab lus sib xyaw. Yog hais tias koj tam sim no ntxiv txhaj tshuaj ntawm hydrogen peroxide, koj yuav tsis pom ib qho decomposition ntawm hydrogen peroxide. Yog vim li cas yog qhov tsim ntawm cov hlau ion ruaj khov heev nrog EDTA (qhov no reagent reacts nrog ntau cov hlau ions, uas yog siv los txiav txim thiab tshem tawm ntawm ib puag ncig). Kev sib xyaw ntawm Fe ions³⁺ nrog EDTA thaiv qhov chaw ua haujlwm ntawm cov enzyme thiab yog li ua tsis tau catalase (4).

Hlau kab tshoob nplhaib

Nyob rau hauv analytical chemistry, kev txheeb xyuas ntawm ntau ions yog nyob ntawm qhov tsim ntawm sparingly soluble precipitates. Txawm li cas los xij, qhov nrawm nrawm ntawm lub rooj solubility yuav qhia tau tias nitrate (V) thiab nitrate (III) anions (cov ntsev ntawm yav dhau los tsuas yog hu ua nitrates, thiab tom kawg - nitrites) xyaum tsis tsim cov dej nag.

Hlau (II) sulfate FeSO tuaj rau kev cawm hauv kev kuaj xyuas cov ions no.₄. Npaj cov reagent. Ntxiv nrog rau cov ntsev no, koj yuav xav tau ib qho kev daws teeb meem ntawm sulfuric acid (VI) H₂SO₄ thiab diluted 10-15% daws ntawm cov kua qaub no (yuav ceev faj thaum diluting, ncuav, tau kawg, "acid rau hauv dej"). Tsis tas li ntawd, cov ntsev uas muaj cov tshuaj anions, xws li KNO₃, NaJ₃, NaJ₂. Npaj ib qho kev daws teeb meem FeSO.₄ thiab kev daws ntawm ntsev ntawm ob qho tib si anions (ib feem peb ntawm ib teaspoon ntsev yog yaj nyob rau hauv txog 50 cm³ dej).

5. Cov txiaj ntsig zoo ntawm lub nplhaib kuaj.

Cov reagents tau npaj txhij, nws yog lub sijhawm los sim. Ncuav 2-3 cm rau hauv ob lub raj³ FeSO solution₄. Tom qab ntawd ntxiv ob peb tee ntawm concentrated N tov.₂SO₄. Siv lub pipette, sau ib qho aliquot ntawm cov tshuaj nitrite (xws li NaNO₂) thiab ncuav nws mus rau hauv kom nws ntws los ntawm phab ntsa ntawm lub raj (qhov no yog qhov tseem ceeb!). Nyob rau hauv tib txoj kev, ncuav nyob rau hauv ib feem ntawm cov ntsev ntsev (piv txwv li, KNO₃). Yog tias koj ua tib zoo ncuav ob qho kev daws teeb meem, lub voj voog xim av yuav tshwm rau saum npoo (li no lub npe rau qhov kev sim no - lub nplhaib cov tshuaj tiv thaiv) (5). Cov nyhuv yog qhov nthuav, tab sis koj muaj cai poob siab, tej zaum txawm indignant (Qhov no yog ib qho kev ntsuam xyuas, tom qab tag nrho?

Txawm li cas los xij, ua lwm yam kev sim. Lub sijhawm no ntxiv dilute H.₂SO₄. Tom qab qhia cov kev daws teeb meem ntawm nitrates thiab nitrites (raws li ua ntej), koj yuav pom qhov tshwm sim zoo hauv ib lub raj kuaj - ib qho nrog cov tshuaj NaNO.₂. Lub sij hawm no, tej zaum koj yuav tsis muaj lus hais txog qhov muaj txiaj ntsig ntawm kev ntsuas lub nplhaib: cov tshuaj tiv thaiv hauv nruab nrab acidic me ntsis tso cai rau koj kom paub qhov txawv ntawm ob ions.

Cov txheej txheem tshuaj tiv thaiv yog ua raws li kev decomposition ntawm ob hom nitrate ions nrog kev tso tawm ntawm nitrogen oxide (II) TSIS MUAJ (qhov no, cov hlau ion yog oxidized los ntawm ob-rau peb-tus lej). Kev sib xyaw ua ke ntawm Fe (II) ion nrog NO muaj xim xim av thiab muab lub nplhaib xim (yog tias qhov kev sim ua kom raug, los ntawm kev sib xyaw cov kev daws teeb meem koj tsuas yog tau txais cov xim tsaus nti ntawm lub raj tshuaj ntsuam, tab sis - koj yuav tsum. lees - nws yuav tsis zoo li qhov ntxim nyiam). Txawm li cas los xij, qhov decomposition ntawm nitrate ions yuav tsum muaj cov tshuaj tiv thaiv acidic nruab nrab, thaum nitrite tsuas yog xav tau me ntsis acidification, yog li pom qhov sib txawv hauv kev sim.

Hlau hauv Kev Pabcuam zais cia

Tib neeg yeej ib txwm muaj ib yam dab tsi los nkaum. Lub creation ntawm phau ntawv journal kuj entailed txoj kev loj hlob ntawm txoj kev los tiv thaiv xws kis cov ntaub ntawv - encryption los yog zais cov ntawv nyeem. Ntau yam ntawm cov sympathetic inks tau tsim rau txoj kev tom kawg. Cov no yog cov khoom uas ua rau koj ua rau lawv daim ntawv sau tsis pomTxawm li cas los xij, nws tau tshwm sim nyob rau hauv kev cuam tshuam ntawm, piv txwv li, cua sov lossis kev kho mob nrog lwm yam tshuaj (tus tsim tawm). Npaj tus cwj mem zoo nkauj thiab nws tus tsim tawm tsis yog qhov nyuaj. Nws yog txaus kom nrhiav tau cov tshuaj tiv thaiv nyob rau hauv uas cov khoom xim yog tsim. Nws yog qhov zoo tshaj plaws uas tus cwj mem nws tus kheej tsis muaj xim, ces cov ntawv sau los ntawm lawv yuav pom tsis pom ntawm lub substrate ntawm ib qho xim.

Iron compounds kuj ua rau cov inks txaus nyiam. Tom qab ua tiav cov kev ntsuam xyuas yav dhau los, cov kev daws teeb meem ntawm cov hlau (III) thiab FeCl chloride tuaj yeem raug npaj ua cov kua nplaum.₃, potassium thiocyanide KNCS thiab potassium ferrocyanide K₄[Fe(CN)]₆]. Hauv cov tshuaj tiv thaiv FeCl₃ nrog cyanide nws yuav tig liab, thiab nrog ferrocyanide nws yuav tig xiav. Lawv zoo dua li inks. Kev daws teeb meem ntawm thiocyanate thiab ferrocyanidetxij li thaum lawv tsis muaj xim (hauv qhov kawg, cov tshuaj yuav tsum tau diluted). Cov ntawv sau tau ua nrog cov tshuaj daj daj ntawm FeCl.₃ nws tuaj yeem pom ntawm daim ntawv dawb (tshwj tsis yog daim npav kuj yog daj).

6. Ob lub suab mascara zoo

7. Sympathetic salicylic acid number case

Npaj diluted daws ntawm tag nrho cov ntsev thiab siv ib tug txhuam los yog match sau rau ntawm daim ntawv nrog ib tug tov ntawm cyanide thiab ferrocyanide. Siv cov txhuam hniav sib txawv rau txhua tus kom tsis txhob kis cov tshuaj reagents. Thaum qhuav, muab cov hnab looj tes tiv thaiv thiab moisten cov paj rwb nrog cov tshuaj FeCl.₃. Hlau (III) chloride tov corrosive thiab tawm cov pob daj uas tig xim av dhau sijhawm. Vim li no, tsis txhob staining ntawm daim tawv nqaij thiab ib puag ncig nrog nws (ua qhov kev sim ntawm lub tais). Siv ib lub paj rwb swab kov ib daim ntawv kom dampen nws nto. Raws li tus tsim tawm, cov ntawv liab thiab xiav yuav tshwm sim. Nws kuj tseem tuaj yeem sau nrog ob tus lej ntawm ib daim ntawv, tom qab ntawd cov ntawv sau qhia yuav yog ob-xim (6). Salicylic cawv (2% salicylic acid hauv cawv) kuj tsim nyog ua tus cwj mem xiav (7).

Qhov no xaus lus peb tshooj ntawm hlau thiab nws cov tebchaw. Koj pom tias qhov no yog lub hauv paus tseem ceeb, thiab ntxiv rau, nws tso cai rau koj los ua ntau yam kev sim siab. Txawm li cas los xij, peb tseem yuav tsom mus rau lub ntsiab lus "hlau", vim tias hauv ib hlis koj yuav ntsib nws tus yeeb ncuab phem tshaj plaws - corrosion.

Saib kuj: