▁ ▁Chem ical ▁components ▁ ▁The ▁main ▁components ▁of ▁s oda ▁l ime ▁are ▁Cal ci um ▁hydro x ide , ▁Ca ( OH ) 2 ▁( about ▁ 7 5 %) ▁Water , ▁H 2 O ▁( about ▁ 2 0 %) ▁S od ium ▁hydro x ide , ▁Na OH ▁( about ▁ 3 %) ▁Pot ass ium ▁hydro x ide , ▁K OH ▁( about ▁ 1 %). ▁ ▁Ana est h etic ▁use ▁During ▁the ▁administration ▁of ▁general ▁an a est hes ia , ▁the ▁g ases ▁exp ired ▁by ▁a ▁patient , ▁which ▁contain ▁carbon ▁dio x ide , ▁are ▁passed ▁through ▁an ▁an a est h etic ▁machine ▁breath ing ▁circuit ▁filled ▁with ▁s oda ▁l ime ▁gran ules . ▁Medical - grade ▁s oda ▁l ime ▁includes ▁an ▁indicating ▁d ye ▁that ▁changes ▁color ▁when ▁the ▁s oda ▁l ime ▁reaches ▁its ▁carbon ▁dio x ide ▁absor bing ▁capacity . ▁ ▁To ▁ensure ▁that ▁a ▁s oda ▁l ime ▁can ister ▁( CO 2 ▁absor ber ) ▁is ▁function ing ▁properly , ▁it ▁should ▁not ▁be ▁used ▁if ▁the ▁indicating ▁d ye ▁is ▁activ ated . ▁Standard ▁an a est hes ia ▁machines ▁typically ▁contain ▁up ▁to ▁ 2   kg ▁of ▁s oda ▁l ime ▁gran ules . ▁ ▁Lith ium ▁hydro x ide ▁( Li OH ) ▁is ▁the ▁alk ali ▁hydro x ide ▁with ▁the ▁lowest ▁mole cular ▁weight ▁( Na : ▁ 2 3 ▁g / m ol ; ▁Li : ▁