Law kom muaj sib npaug

The Great phau ntawv txhais lus ntawm cov lo lus sib npaug (Latin suab zoo li aequivalens) piav yuav ua li cas ib yam dab tsi sib npaug, los yog sib npaug yog ib qho sib npaug mus rau lwm lub, hais tias nws yuav yooj yim hloov. Nyob rau hauv Science News for KIDS, kev cai lij choj ntawm kom muaj sib npaug (siv txij thaum lub caij 18th cov xyoo pua, nws yog qhia nyob rau hauv tsev kawm ntawv, thov chemists thiab biologists los ntawm ntau lub teb chaws nyob rau hauv kev tshawb xav thiab nyob rau hauv kev xyaum) qhia tias tag nrho cov tshuaj li cas nyob rau hauv kev faib ua feem rau lawv cov sib npaug. Qhib txoj cai yog ib tug German chemist I. Richter, uas nws ua hauj lwm tau ntev tau paub. Nyob rau hauv nws cov peb-volume ua hauj lwm luam tawm nyob rau hauv lub sij hawm ntawm 1792 mus 1794 xyoo, hu ua "Principles of stoichiometry, los yog ib txoj kev ntsuas cov tshuaj hais", Academic pom tau tias cov tshuaj li cas yooj yim piv. Lawv kuj nkag tau ib lub sij hawm xws li "stoichiometry". Tam sim no nws yog ib tug tag nrho seem ntawm Science News for KIDS, uas qhia txog tus piv ntawm cov reactants nkag mus rau hauv tshuaj sis raug zoo.

Richter thawj nyob rau hauv nws tej hauj lwm coj ntau cov tshuaj tiv thaiv sib npaug. Lawv sawv cev rau ib tug nyob ntawm nkag uas muaj qhov zoo thiab ntau ntaub ntawv hais txog cov txheej txheem uas tshwm sim nyob rau hauv lub sis ntawm txawv tshuaj hu ua reagents. Txawm thaum lub sij hawm alchemical science rau denote yooj yim hais soj ntsuam siv txawv cim tom qab Formula complex (muaj ob peb cov ntsiab) yog nrhiav tau tshuaj. Tab sis I. V. Rihter (nyob rau hauv tus ntawm nws tus kws qhia ntawv thiab philosopher Emanu-es Kant, uas yuav lav hais tias muaj tej qhov chaw ntawm lub natural sciences muaj ntau li ntau yeej muaj tseeb science raws li nws muaj kev kawm txog zauv) siv nyob rau hauv lub tswv yim sib cav txog tshuaj lom neeg cov qauv thiab lub sij hawm "stoichiometry", piav cov tshuaj tiv thaiv ntawm lub ntau kab zauv thiab qhib ib txoj cai kom muaj sib npaug. Cov mis, nws qhia yuav sau: E2 • m1 = E1 • m2. Qhov twg m1 thiab m2 - ceeb thawj yam yog "1" thiab "2", unreacted, thiab A1 thiab A2 - nws yog lawv tshuaj kom muaj sib npaug.

Yuav kom to taub txoj cai kom muaj sib npaug, nws yog tsim nyog los qhia kom meej hais tias sib npaug - yog ib tug zoo tiag tiag tooj los yog ib yam khoom uas yuav muab cov hydrogen ntawv nyob rau hauv lub acid-alkali cov tshuaj tiv thaiv los yog electron raws li ib tug tshwm sim ntawm redox tshua. Equivalent loj - ib tug loj ntawm ib tug sib npaug. Nws yog ntseeg hais tias ib tug sib npaug reacts tshuaj (los yog displaces) nrog 1 gram ntawm hydrogen los yog cov pa nrog 8 grams los yog 35,5 grams ntawm chlorine. Nyob rau hauv kev xyaum, tus nqi ntawm cov tshuaj yeeb dej caw sib npaug nquag muaj ib tug heev me me luaj li cas, vim li ntawd nws yog feem ntau qhia nyob rau hauv moles. Nyob rau hauv ib lub tias muaj ib tug tsis tu ncua nyiaj ntawm hais (atoms, ions los yog molecules) yog sib npaug zos rau cov xov tooj Avagadro: NA = 6,02214179 (30) × 1023. Nyhav ntawm ib tug tias ntawm lub substance, qhia nyob rau hauv grams, yog txaus sib npaug zos rau nws hnyav nyob rau hauv atomic loj units.

Raws li muaj sib npaug ntawm kev cai lij choj, peb yuav qhia tias cov acid-puag titration ntws los ntawm cov kab zauv ntawm cov tshuaj tiv thaiv: Koh + HCl → KCl + H2O, uas ua los ntawm cov kev sis raug zoo ntawm 1 tias ntawm poov tshuaj hydroxide nrog 1 tias ntawm hydrochloric acid yog tau 1 tias ntawm ntsev hu ua poov tshuaj tshuaj dawb, thiab 1 tias ntawm cov dej. Hais tias yog, qhov sib npaug luj ntawm poov tshuaj hydroxide sib npaug E Koh = 39 + 16 + 1 = 56 g hydrochloric acid - E HCl = 1 + 35 = 36 g, poov tshuaj tshuaj dawb - E KCl = 39 + 35 = 74 g, dej - E H2O = • 2 1 + 16 = 18 Nyob rau hauv thiaj li hais tias tag neutralize 56 g ntawm poov tshuaj hydroxide tsim nyog mus rau 36 g ntawm hydrochloric acid. Cov tshwm sim yuav tsum tau 74 g ntawm poov tshuaj tshuaj dawb thiab 18 g ntawm cov dej. Tab sis txij thaum txoj cai hais tias tus luj tshuaj, unreacted proportional rau lawv kom muaj sib npaug, ces paub tus nqi ntawm cov reagent yuav xam ntau npaum li cas yuav nkag mus rau hauv cov tshuaj tiv thaiv los yog tus thib ob reagent rau xam cov khoom tawm los.

Piv txwv li, raws li yuav poov tshuaj tshuaj dawb, yog hais tias nws yog lub npe hu hais tias hydrochloric acid kiag neutralized los ntawm 100 g ntawm poov tshuaj hydroxide? Siv cov kev cai lij choj ntawm kom muaj sib npaug, yuav tsum sau ib daim ntawv: 56 • mKCl = 74 • 100. Ces mKCl = (74 • 100) / 56 = 132 A ntawm hydrochloric acid rau neutralize lub poov tshuaj hydroxide yuav tsum tau 100 64 100 Yog hais tias lub nroog g poov tshuaj hydroxide rau neutralize lub sulfuric acid: 2KOH + H2SO4 → K2SO4 + 2H2O, ces nws yuav tsum tau ib tug sib txawv heev npaum li cas ntawm acid. Raws li qhia los ntawm lub stoichiometric coefficients ntawm no cov tshuaj tiv thaiv, 2 moles ntawm poov tshuaj hydroxide hnov mob 1 tias ntawm sulfuric acid thiab cov no ib tug 1 tias ntawm poov tshuaj sulfate thiab 2 tus nas ntawm cov dej. Paub txog dab tsi luj ntawm unreacted tshuaj proportional sib npaug tes taw hnyav li, ib tug yuav sau: 2 • 56 • 98 • mH2SO4 = 100, ces 100 rau neutralize lub poov tshuaj hydroxide yuav tsum tau mH2SO4 = 88 g ntawm sulfuric acid. Qhov no ntaub ntawv 155 g ntawm poov tshuaj sulphate. Tus nqi ntawm cov dej allotted los ntawm neutralization ntawm 100 g ntawm poov tshuaj hydroxide hydrochloric los yog sulfuric acid, yuav tsum yog tib yam thiab sib npaug zos rau 32 g.

Siv kom muaj sib npaug Tsab cai Science News for KIDS (analytical, inorganic, organic, thiab lwm yam) rau txoj kev kawm ntaub ntawv thiab lwm yam thwmsim raws li nyob rau hauv lub xam ntawm qhov nqi koj tshuav ntawm cov tshuaj tshua. Nyob rau hauv tas li ntawd, nws yog siv (rau kev npaj ntawm cov ntaub ntawv uas balances) nyob rau hauv lub tsim thiab cov lag luam ntawm txoj kev kuaj, pilot los yog muaj sib rau lub synthesis ntawm tshuaj. Lawv lossi siv cov tshwj xeeb ntawm cov tshuaj, kev kho mob, lom, muaj kab mob-epidemiological lub chaw soj nstuam, vim nws yog lub hauv paus ntawm cov qauv uas lub xam uas muaj ntau xeem.