Nyob rau hauv cov txheej txheem ntawm cov tshuaj tiv thaiv, dab tsi yog theoretically npaj tsis yog ib txwm tau, yam tsawg kawg nkaus. Qhov no feem ntau yog vim muaj cov tshuaj tiv thaiv nyuaj - qhov kub tsis zoo, kev sib cuag tsis txaus nrog cov catalyst, thiab tsuas yog cov tshuaj tsis huv ntawm cov reagents. Nyob rau hauv cov ntaub ntawv no, chemists siv cov kab lus "ntau seem ntawm cov yield."
Lub tswv yim no suav nrog tus nqi tshwj xeeb - feem pua ntawm cov txiaj ntsig tau txais los ntawm qhov yuav tsum tau muaj tshuaj lom neeg. Denoted los ntawm tsab ntawv "omega". Cov nqi no yuav tsum raug coj mus rau hauv tus account, feem ntau cov tub ntxhais kawm tsis nco qab suav ib feem me me. Nws yog qhov kev poob siab tshwj xeeb hauv ntau hom kev sim - lub tsheb ciav hlau ntawm kev xav yog qhov tseeb, thiab kev kuaj xyuas tus qauv yuav tso cai rau feem ntau ntawm cov qhab nia rau kev ua hauj lwm suav - thiab hauv kev sim nws yog nyob rau hauv xws li trifles uas lawv "catch". Lawv txawm muab cov kev xaiv rau cov lus teb, noj mus rau hauv tus account xws li ib tug yuam kev. Nws yooj yim mus ntes tau. Yog li ua ntej yuav daws qhov teeb meem, xyuas seb puas muaj "feem ntau ntawm cov zis" parameter.
Muaj lwm tus, zoo lisuab tswvyim. Lo lus "mass feem" nws tus kheej tuaj yeem ua ke nrog lwm cov ntsiab lus. Thiab ces nws hloov tawm, piv txwv li, qhov kev faib ua feem ntawm cov khoom nyob rau hauv lub ore. Ntawd yog, koj muaj ib qho khoom siv uas tsuas yog ib feem tuaj yeem hnov mob. Thiab qhov no yuav tsum tau coj mus rau hauv tus account hauv kev suav, txwv tsis pub koj yuav raug poob rau hauv lub ntxiab, xws li lub tswv yim ntawm "feem ntau ntawm cov zis." Kuj ntes tau ntse thiab ntau. Saib xyuas!
Puas muaj ib feem ntawm cov khoom hauv cov khoom sib xyaw hauv qhov xwm txheej? Qhov no txhais tau hais tias nws cov atoms ua ib feem pua ntawm qhov loj hauv cov teeb meem. Nyob rau hauv txoj cai, rau chemists thiab lovers ntawm complex kev daws teeb meem, cov loj feem yuav pab tau rau kev suav nrog cov tshuaj tiv thaiv sib npaug. Cov ntaub ntawv no kuj tseem muaj txiaj ntsig yog tias koj xav tsim cov qauv ntawm cov khoom. Tsuas yog ceev faj - muaj cov tshuaj isomer thiab cov tshuaj uas muaj cov qauv sib npaug zoo sib xws. Koj yuav xav tau cov tshuaj tiv thaiv kab mob los tsim cov qauv tseeb. Tab sis qhov no tsis yog qib tsev kawm, tab sis Chemistry Olympiad.
Hauv kev muaj tiag, feem ntau txhua txoj haujlwm yooj yim dua, cov menyuam kawm ntawv raug sim los ntawm kev paub txog cov qauv qis thiab muaj peev xwm ua haujlwm lej yooj yim, tsis txhob hnov qab txog cov atoms ib molecule. Yuav ua li cas yog qhov loj feem ntawm ib lub caij xam? Siv lub rooj, nrhiav qhov hnyav atomic ntawm lub caij koj tab tom nrhiav, muab faib los ntawm tus lej ntawm cov atoms hauv lub molecule. Qhov no yog tus lej. Thiab tus denominator yuav tsum muaj qhov hnyav molecular ntawm ib chav tsev ntawm cov khoom ntawm tag nrho cov mis, uas yog, koj lub caij nrog rau qhov tsim nyog yam tseem ceeb thiab tag nrho lwm yam loj ntawm cov ntsiab lus multiplied los ntawm lawv tus xov tooj nyob rau hauv lub molecule. Piv txwv li, qhov hnyav molecular ntawm cov dej molecule yog 16(oxygen), ntxiv ob lub hydrogen atoms (1+1). Tag nrho 18. Cov feem loj ntawm cov khoom siv hydrogen yog yooj yim: faib 2 los ntawm 18. Yog tias tsim nyog, muab faib los ntawm ib puas feem pua, tab sis cov feem ntawm ib chav tsev kuj tseem ua tau. Los ntawm kev sib piv, ua nws nyob rau hauv ntau cov qauv thaum muaj peb lossis ntau lub ntsiab.
pawg feem ntau raws li lub tswv yim kuj siv rau kev daws teeb meem. Tus lej yog qhov loj ntawm cov tshuaj, tus denominator yog qhov hnyav ntawm qhov hnyav ntxiv rau qhov loj ntawm cov tshuaj.
Yog tias koj ceev faj thiab nkag siab txhua qhov tshwm sim, koj yuav tsis raug ntes nyob rau theem qis. Thiab nws yuav tsis txaj muag vim qhov qhab nia qis, thaum txhua yam zoo li tau txiav txim siab, tab sis qhov tshwm sim tsis tau txhawb nqa. Cia li khaws cov ntsiab lus hauv siab. Kawm thiab xyaum ua tej haujlwm tshwj xeeb. Thaum koj tau txais koj txhais tes, txhua yam teeb meem yuav dhau los.
