Tus kwv tij molecular yuag - ib lub cev muaj nuj nqis yam ntxwv ntawm txhua yam khoom uas

Tes taw hnyav li molecules, zoo li atomic loj, heev me me. Yog li ntawd, rau lawv cov kev sib piv nrog muab xam siv atomic loj unit. Tus kwv tij molecular yuag compound - qhov no lub cev magnitude, uas yog tus piv ntawm qhov ceeb thawj ntawm cov compound molecule rau 1/12 ntawm cov kev faib ua feem ntawm cov pa roj carbon atoms. Qhov no Performance index qhia tias pes tsawg lub sij hawm tus luj ntawm tag nrho cov molecule ntau tshaj 1/12 ntawm tus luj ntawm lub elementary hais ntawm carbon thiab, zoo li tej neeg txheeb ze tus nqi twb tsis muaj dimension thiab yog denoted los ntawm lub cim ntawm Mr.

Mr (compound) = m (molecule compound) / 1/12 m (C). Txawm li cas los, nyob rau hauv kev xyaum, nws yuav siv ib tug txawv tswvyim rau xam cov nqi no. Nyob rau hauv raws li lub voj hlua, cov txheeb ze molecular loj sib npaug zos rau tag nrho cov nqi ntawm cov txheeb ze atomic masses (Ar) ntawm tag nrho cov tshuaj ntsiab uas tsim lub compound raws li tus xov tooj ntawm elementary hais ntawm txhua lub caij, i.e. Nws yuav tsum muab sau schematically raws li nram no:

Mr (B1xC1y) = x * Ar (B1) + y * Ar (C1).

Yuav kom txiav txim raug nqi no yuav tsum:

1. paub cov tshuaj mis ntawm lub substance;
2. Ar txiav txim raug nyob rau hauv lub rooj D. I. Mendeleeva (li worthwhile yog lub xov tooj tom qab tus zauv point yog sib npaug los yog privyshaet 5, ces pub muab kwv yees mus rau qhov ze tag nrho tsev ntxiv: piv txwv li, Ar (Li) = 6, 941, los xam siv integer uas yog 7, thiab yog hais tias lub xov tooj yog tsawg tshaj li 5, ces qhov kev kawm xws li hais tias muaj yog ib tug: Ar (K) = 39,098, i.e., coj 39).
3. thaum xam Mr tsis txhob hnov qab mus rau hauv tus account lub xov tooj ntawm atoms, i.e., Federation sawv ntawm lub ntsiab nyob rau hauv lub compound.

Tus kwv tij molecular loj, lub mis uas yog schematically qhia saum toj no siv tau rau cov complex tebchaw. Vim hais tias kev muab xam rau ntawm cov ntau y yooj yim tshuaj txaus los mus txiav txim tsuas yog tus neeg txheeb ze atomic loj ntawm lub periodic rooj thiab optionally khoo los ntawm cov xov tooj ntawm elementary hais. Piv txwv li: Mr (P) = Ar (R) = 31 thiab Mr (N ₂₎ = 2 * Ar (N) = 2 * 14 = 18.

Xav txog lwm cov piv txwv, thiab paub dab tsi yog qhov kwv tij molecular loj ntawm cov dej - ib tug complex teeb meem. Lub empirical mis ntawm lub substance yog H ₂ O, i.e., nws muaj ob hydrogen atoms thiab ib cov pa atom. Yog li ntawd, qhov kev txiav txim cov ntaub ntawv zoo li no:

Mr (H ₂ O) = 2 * Ar (H) + Ar ( O) = 2 * 1 + 16 = 18

Koj muaj peev xwm sau nyob rau hauv luv luv, xa me nyuam rov ib literal qhia. Qhov no xam qhia tau hais tias Mr 18 lub sij hawm ntau tshaj 1/12 ntawm ib lub tsev particle loj carbon. Ib yam li ntawd txiav txim txheeb ze molecular ceeb thawj los ntawm tej tshuaj compound, nyob rau hauv cov mob uas nws cov empirical mis no paub. Tab sis kuj, siv no tus nqi, koj yuav tau rov qab kho cov zoo thiab ntau pes tsawg leeg tsis paub hais tias yam, tsim kom muaj cov ntsiab lus ntawm ib tug neeg nuclides. Nyob rau hauv kev xyaum, rau qhov kev txiav txim ntawm Mr tshuaj ua hauj lwm physico-tshuaj hom kev kawm, xws li distillation, loj spectrometry, roj chromatography , etc. Yuav kom txiav txim no Performance index rau lub polymers siv txoj kev raws li nyob rau hauv colligative zog (txiav txim tus naj npawb ntawm ob bonds, tej pab pawg neeg, lub viscosity, lub teeb scattering muaj peev xwm).

Yog li, tus kwv tij molecular loj cov yam ntxwv ntawm txhua yam khoom uas thiab yuav ib tug neeg mus rau nws. Qhov no tus nqi yog txiav txim rau ob qho tib si yooj yooj yim thiab complex tebchaw, inorganic thiab organic. Nws tsis yog tshwj xeeb yog ib qho tseem ceeb nyob rau hauv txoj kev kawm thiab synthesizing polymers uas nws zog yuav nyob ntawm seb qhov taw qhia ntawm molecular ceeb thawj.