Poov tshuaj chromate. Kev npaj ntawm cov tshuaj thiab lub zog. daim ntawv thov

poov tshuaj chromate los yog poov tshuaj hromovoloknisty (thoob ntiaj teb lub npe: Kalium chromicum, Kaliumchromat, poov tshuaj chromate) - yog ib tug inorganic compound, daj muaju ntawm lub orthorhombic system, soluble nyob rau hauv cov dej. Nws yog hais txog ntsev ntawm chromic acid H2CrO4, uas nyob rau hauv cov dawb lub xeev tsis muaj nyob. Nyob rau hauv tshuaj poov tshuaj chromate nram qab no mis: CrK2O4

Yuav ua li cas kom tau poov tshuaj chromate?

Hromovoloknisty poov tshuaj tau nyob rau hauv ob peb txoj kev:

1. Los ntawm chromium oxide oxidation poov tshuaj chlorate (cov tshuaj tiv thaiv yuav siv sij hawm qhov chaw nyob rau ib tug kub ntawm 500-700 degrees):

Cr2O3 (chromium oxide) + KClO3 (poov tshuaj chlorate) + K2CO3 (poov tshuaj carbonate) = 2K2CrO4 (poov tshuaj chromate) + KCl (poov tshuaj tshuaj dawb) + 2CO2 (carbonic acid gas)

2. Los ntawm dissolving lub chromium oxide nyob rau hauv poov tshuaj hydroxide :

CrO3 (chromium oxide) + 2KOH (poov tshuaj hydroxide) = K2CrO4 (poov tshuaj chromate) + H2O (dej)

3. Los ntawm decomposition ntawm poov tshuaj dichromate los ntawm cua sov (cov tshuaj tiv thaiv yog nqa tawm ntawm ib tug kub ntawm 500-600 degrees):

4K2Cr2O7 (poov tshuaj dichromate) = 4K2CrO4 (poov tshuaj chromate) + 2Cr2O3 (chromium oxide) + 3O2 (oxygen)

4. Los ntawm raug mus rau ib tug concentrated tshuaj ntawm poov tshuaj hydroxide rau poov tshuaj dichromate :

K2Cr2O7 (poov tshuaj dichromate) + 2KOH (poov tshuaj hydroxide) = 2K2CrO4 (poov tshuaj chromate) + H2O (dej)

5. Qhov xwm ntawm tus tsis tshua muaj mineral uas yog hu ua "tarapakait". Nws hromovoloknisty poov tshuaj hlau.

Poov tshuaj chromate tshuaj zog:

1. Nyob rau hauv nta acids hromovoloknisty poov tshuaj nkag mus rau potassium dichromate, uas nws mis K2Cr2O7. Ib qho piv txwv yog cov nram qab no cov tshuaj tiv thaiv:

2K2CrO4 (poov tshuaj chromate) + 2HCl (hydrochloric acid diluted) = K2Cr2O7 (poov tshuaj dichromate) + 2KCl (poov tshuaj tshuaj dawb) + H2O (dej)

2. Nyob rau hauv nrog muaj zog acids muaj ib tug txawv cov tshuaj tiv thaiv yuav siv sij hawm qhov chaw, piv txwv li:

K2CrO4 (poov tshuaj chromate) + 2HCl (hydrochloric acid nyob rau hauv feeb meej daim ntawv no) K = (Kr (Cl) O3) (complexed chromium) + KCl (poov tshuaj tshuaj dawb) + H2O (dej)

3. Nyob rau hauv cov tshuaj tiv thaiv nrog poov tshuaj chromate kub concentrated acids sau oxidizing zog. Ib qho piv txwv yog lub nram qab no cov tshuaj tiv thaiv yog nqa tawm ntawm ib tug kub ntawm 90 degrees:

2K2CrO4 (poov tshuaj chromate) + 16HCl (hydrochloric acid) = 2CrCl3 (chromium chloride) + 3Cl2 (raws li cov tshuaj gas) + 4KCl (poov tshuaj tshuaj dawb) + 8H2O (dej)

4. Hromovoloknisty poov tshuaj tej zaum yuav nkag rau hauv pauv tshua. Piv txwv li:

K2CrO4 (poov tshuaj chromate) + 2AgNO3 (silver nitrate) = Ag2CrO4 (silver chromate, precipitates) + 2KNO3 (poov tshuaj nitrate)
K2CrO4 (poov tshuaj chromate) + Hg2 (NO3) 2 (mercury nitrate) = Hg2CrO4 (mercury chromate precipitates) + 2KNO3 (poov tshuaj nitrate)

Lub lub zog ntawm poov tshuaj chromate:

1. Cov kev ceev yog 2,732 g / cm3.
2. poov tshuaj chromate melts ntawm 968,3 ° C. Thaum ib tug kub ntawm 668 degrees nkag mus rau hauv liab hexagonal theem - acquires lwm cov xim - liab. Txawm li cas los, raws li qhov txias los ua daj dua.
3. Cov ntaub ntawv daj muaju rhombic system.
4. Nws belongs rau qhov chaw pab pawg neeg P-yeej.
5. Yog cov lub paramagnetic.
6. Tsis soluble nyob rau hauv ethanol, insoluble nyob rau hauv cov dej. Soluble nyob rau hauv ethyl cawv thiab diethyl.
7. Cov hniav puas loj yog 194,19 g / mol.

Kho qhov muag khoom ntawm poov tshuaj chromate:

Lub refractive index ntawm 1,74

Qhov uas siv tau poov tshuaj chromate?

1. Cov tawv kev lag luam yog siv raws li ib tug tanning tus neeg saib xyuas. Nyob rau hauv dyeing ntawm fabrics siv raws li ib tug mordant.
2. Nws yog siv raws li ib feem ntawm cov ntsha muaj pes tsawg leeg ntawm ib tug tshwj xeeb tshuaj degreasing.
3. Raws li brightener rau ciab thiab roj.
4. Nyob rau hauv cov organic synthesis raws li ib tug oxidant, piv txwv li, nyob rau hauv qhuav ntawm dyes.
5. Tsis tas li ntawd hromovoloknisty poov tshuaj tshuaj siv rau kev npaj ntawm electrochemical oxidation nyiaj, thiab rau zaj ntawm cov khoom los ntawm tooj liab thiab nyiaj alloys.
6. siv raws li ib tug homeopathic tshuaj nyob rau hauv cov tshuaj.
7. Nyob rau hauv lub chaw soj nstuam cav ntxuav tais diav yog ib tug sib tov ntawm vaj huam sib tagnrho cov concentrated sulfuric acid thiab K2Cr2O7 tshuaj, yav tas los nyeem nyob rau hauv lub txias.

Poov tshuaj dichromate (lub npe - Chrompick)

Nws nruab nrab muaju ntawm liab-txiv kab ntxwv xim. Tsis crystalline cov ntaub ntawv, muaj ib tug ntom ntawm 2,684 gram ib nyhav centimeter, melts nyob rau hauv 397 degrees. Nyob rau ntxiv cua kub decomposes. Solubility nyob rau hauv dej nyob rau hauv 20 degrees yog sib npaug zos rau 12,48 grams ntsev rau ib 100 grams dej. Poov tshuaj dichromate yog dav siv raws li ib tug oxidant nyob rau hauv lub pyrotechnics, lub match kev lag luam, thiab raws li ib tug reagent nyob rau hauv hromametrii.