Zoo tshuaj

Qhov no ceg ntawm science li analytical Science News for KIDS, kawm cov muaj pes tsawg leeg thiab qauv ntawm tshuaj. Nws yog siv rau txoj kev tshawb no ntawm tsis paub hais tias tebchaw los yog mixtures. Zoo tsom xam seb puas muaj tus muaj los yog tsis tuaj kawm ntawv ntawm cov ntsiab los yog radicals nyob rau hauv lub tshuaj compound, thiab cov quantitative tsom xam muaj xws li kev txiav txim ntawm ib tug tshuaj tshuaj nyob rau hauv tus qauv, i.e., tus xov tooj ntawm Cheebtsam constituting lub sib tov. Rau qhov zoo tsom xam ntawm txoj kev siv cov yam ntxwv ntawm tej ntsiab ntawm cov tshuaj tshua uas yog ib qho yooj yim ua. Zoo kev ntsuam xyuas tso cai rau cov kev soj xyuas tus yuav tsum los los sis tsis muaj ntawm lawv.

Analytical Science News for KIDS yog tsim tshiab thiab paub txoj kev ntawm tsom xam thiab lawv ua daim ntawv thov, raws li tau zoo raws li txoj kev tshawb no ntawm lub theoretical lub hauv paus ntawm analytical dab. Cov txawj nyob rau hauv tus kheej tshuaj, lub cev thiab physico-tshuaj txoj kev tsom xam. Hauv plawv ntawm ntau ntawm lawv yog cov zoo tshuaj yog siv rau cov tebchaws radicals, thiab hais thiab kuj tebchaw muaj nyob rau hauv nyob tus yeees ntawm cov kev kuaj. Yuav kom kawm tau zoo thiab ntau pes tsawg leeg yog siv:

• elemental tsom xam (txiav txim los ntawm lub elemental muaj pes tsawg leeg);
• molecular tsom xam (los ntawm cov qauv ntawm cov tshuaj tebchaw rau lub molecular theem);
• yam ntxwv tsom xam (ib yam ntawm molecular tsom xam, soj qab qhov spatial qauv ntawm atoms thiab molecules, lawv molecular yuag thiab empirical mis);
• haumxeeb tsom xam (organic tebchaw kawm los ntawm functional pawg).

Yog li, nws yuav tsum tau yuav paub ob inorganic thiab organic tebchaw. Nyob rau hauv lub xub ntiag ntawm tej ntsiab yuav tshwm sim los yog ploj coloration tso tawm los yog yaj precipitate cai effervescence thiab lwm tus neeg. Yog hais tias qhov zoo tshaj ntawm cov tshuaj tiv thaiv yuav xaiv kom raug, i.e. xim (xim) rau ib qho ntawv los yog anion, raws li zoo raws li rhiab heev (i.e., pib nrhiav kom tau pub rau cov me me), qhov tshwm sim yuav tsum tau txhim khu kev qha tshwm sim - lub xaus ntawm lub xub ntiag los yog tsis tuaj kawm ntawv nyob rau hauv ib tug qauv ntawm tes los yog tshuaj yeeb dej caw . Lub hauv paus ntawm no tshuaj ntsuam yog aqueous lub ntsiab ntawm paub ionic zoo tshuaj tiv thaiv.

Rau inorganic tebchaw, lawv feem ntau tshwm sim nyob rau hauv aqueous lub ntsiab, tab sis nyob rau hauv cov ntaub ntawv ntawm alkali hlau cations nrhiav kom tau yog nqa tawm thaum ua qhuav ntsev nyob rau hauv nruab nrab (kub) yog ib feem ntsuj plig teeb nplaim taws. Lub cations ntawm lithium (Li +) yuav xim tus nplaim taws nyob rau hauv ib tug maub liab xim. poov tshuaj cations (K +) - ib tug violet, sodium (Na +) - daj, rubidium (Rb +) - liab, cesium (Cs +) - nyob rau hauv xiav. Zoo tshuaj tiv thaiv cations tej zaum yuav nqa tawm rau barium ntsev: lub xub ntiag ntawm barium cations (Ba2 +) yog muab los ntawm kev ntxiv lub reagent rau sulfate ions (SO42-), txij thaum lub resulting barium sulfate precipitated dawb xim, uas tsis yaj nyob rau hauv acids: Ba2 + + SO42- → BaSO4 ↓. Lub xub ntiag ntawm cov hlau lead ntawv (Pb2 +) pom thaum raug aqueous ntsev tov sulfide (S2-), raws li ib tug tshwm sim ntawm cov hlau lead sulfide yog tsim, uas precipitates raws li ib tug dub precipitate: Pb2 + + S2- → PBS ↓. Tej zoo-paub zoo tshua, ob qho tib si cations thiab anions ntau ntau, thiab lawv yog piav nyob rau hauv Analytical Science News for KIDS.

Thaum xaiv ib tug high-zoo lus teb rau cov xeem qauv, nws yog pab kom paub tias cov kev cai ntawm lub solubility tshuaj tebchaw:

1. Tag nrho nitrates yog soluble.
2. Yuav luag tag nrho cov poov tshuaj, sodium thiab ammonium ntsev yog soluble.
3. Tag nrho chlorides, bromides thiab iodides yog soluble, tsuas yog nyiaj halide, mercury (I) thiab Pb (II).
4. Tag nrho soluble sulfates, tsuas yog barium sulfate, strontium thiab cov hlau lead (II), uas yog insoluble, thiab calcium sulfate thiab nyiaj, uas muaj mob pesnrab soluble.
5. Tag nrho carbonates, sulfites thiab phosphates yog insoluble tsuas yog carbonates, sulphites thiab poov tshuaj phosphates, sodium thiab ammonium.
6. Tag nrho cov insoluble sulfides tsuas yog sulfides ntawm alkali hlau, alkaline ntiaj teb co thiab ammonium.
7. Tag nrho cov insoluble hydroxides tsuas yog alkaline hlau hydroxides. Strontium hydroxide, calcium thiab barium yog sparingly soluble.

Tej organic tshuaj xws li alkanes (paraffin hydrocarbons) los yog alkenes (unsaturated hydrocarbons) yuav kuaj siv ib tug tov ntawm poov tshuaj permanganate, uas nyob rau hauv thawj cov ntaub ntawv yuav hloov tsis tau nws cov xim thiaj li paraffinic hydrocarbons nrog permanganate tsis hnov mob nyob rau hauv lub txias. Nyob rau hauv lub thib ob cov ntaub ntawv, cov tshuaj yuav tsis muaj kob vim to Wagner cov tshuaj tiv thaiv (e.g., ethylene): 2KMnO4 + 3C2H4 + 4H2O - → 2KOH + 3CH2OH-CH2OH + 2MnO2 ↓. Raws li ib tug tshwm sim, dauv ntawm manganese dioxide precipitate muaj ib tug brownish xim. Cov nqaijrog muaj txoj organic tebchaw uas muab tseem ceeb heev functions ntawm tej sia. Lawv loj loj teeb, lub ntsiab txhais ntawm ib tug zoo kawg tswv yim tseem ceeb. zoo haum rau cov nqaijrog siv rau cov hom phiaj, lawv muab faib ua xim thiab lub npe. Nrog lawv pab, nws yuav tsis txiav txim los ntawm cov proteins lawv tus kheej, thiab cov amino acids muaj nyob rau hauv lawv.