tshuaj lom neeg
Acid-base indicators yog cov tebchaw uas tig xim txawv nyob ntawm pH ntawm nruab nrab. Los ntawm ntau yam khoom ntawm hom no, peb yuav xaiv ib khub uas yuav tso cai rau koj los ua qhov kev sim zoo li tsis yooj yim sua.
Qee cov xim yog tsim thaum peb muab lwm cov xim ua ke. Tab sis peb puas yuav tau xiav los ntawm kev sib txuas liab nrog liab? Thiab vice versa: liab los ntawm kev sib xyaw ntawm xiav thiab xiav? Sawv daws yeej yuav hais tsis tau. Leej twg, tab sis tsis yog kws tshuaj, rau leej twg txoj hauj lwm no yuav tsis muaj teeb meem. Txhua yam koj xav tau yog cov kua qaub, lub hauv paus, Congo liab qhia, thiab cov ntawv liab thiab xiav litmus.. Npaj cov tshuaj acidic hauv beakers (xws li los ntawm kev ntxiv me ntsis hydrochloric acid HCl rau dej) thiab cov kev daws teeb meem yooj yim (sodium hydroxide tov, NaOH).
Tom qab ntxiv ob peb tee ntawm Congo liab kua (duab 1), cov ntsiab lus ntawm cov hlab ntsha hloov xim: cov kua qaub ua xiav, alkaline liab (duab 2). Muab daim ntawv xiav litmus rau hauv cov tshuaj xiav (Pic 3) thiab tshem tawm cov ntawv liab litmus (Pic 4). Thaum muab tso rau hauv cov tshuaj liab, daim ntawv liab litmus (daim duab 5) hloov nws cov xim rau xiav (duab 6). Yog li, peb tau ua pov thawj tias tus kws kho mob tuaj yeem ua qhov "ua tsis tau" (duab 7)!
Tus yuam sij rau kev nkag siab qhov kev sim yog qhov kev hloov xim ntawm ob qhov ntsuas. Congo liab tig xiav nyob rau hauv acidic daws thiab liab nyob rau hauv alkaline daws. Litmus ua hauj lwm nyob ib ncig ntawm: nws yog xiav nyob rau hauv bases thiab liab nyob rau hauv acids.
Immersion ntawm daim ntawv xiav (daim ntaub so ntswg soaked nyob rau hauv ib tug alkaline tov ntawm litmus; siv los txiav txim ib tug acidic ib puag ncig) nyob rau hauv ib tug daws ntawm hydrochloric acid hloov cov xim ntawm daim ntawv mus rau liab. Thiab txij li cov ntsiab lus ntawm iav yog xiav (cov nyhuv ntawm kev ntxiv Congo liab ua ntej), peb tuaj yeem xaus tias xiav + xiav = liab! Ib yam li ntawd: daim ntawv liab (blotting ntawv impregnated nrog ib tug acidic tov ntawm litmus; nws yog siv los ntes ib tug alkaline ib puag ncig) nyob rau hauv ib tug daws ntawm caustic soda tig xiav. Yog tias yav dhau los koj tau ntxiv cov tshuaj Congo liab rau lub khob, koj tuaj yeem sau cov txiaj ntsig ntawm kev sim: liab + liab = xiav.
