3.
\(\rm{Na_{2}SO_{3}⋅7H_{2}O}\)是食品工业中常用的漂白剂、抗氧化剂和防腐剂\(\rm{.Na_{2}SO_{3}}\)在\(\rm{30℃}\)时的溶解度为\(\rm{35.5g/100gH_{2}O.}\)
\(\rm{1)}\)计算\(\rm{30℃}\)时\(\rm{Na_{2}SO_{3}}\)饱和溶液中\(\rm{Na_{2}SO_{3}}\)的质量分数\(\rm{ω.(}\)保留\(\rm{2}\)位小数\(\rm{)}\)
\(\rm{2)}\)计算\(\rm{30℃}\)时\(\rm{271g}\) \(\rm{Na_{2}SO_{3}}\)饱和溶液中水的质量.
\(\rm{3)}\)将\(\rm{30℃}\)的\(\rm{Na_{2}SO_{3}}\)饱和溶液\(\rm{271g}\)冷却到\(\rm{10℃}\),析出\(\rm{Na_{2}SO_{3}⋅7H_{2}O}\)晶体\(\rm{79.5g.}\)计算\(\rm{10℃}\)时\(\rm{Na_{2}SO_{3}}\)在水中的溶解度.