10.
\(\rm{Na_{2}S_{2}O_{3}·5H_{2}O}\)俗称“海波”,是常用的脱氧剂和还原剂。它是无色易溶于水的晶体,不溶于乙醇,\(\rm{Na_{2}S_{2}O_{3}·5H_{2}O}\)在\(\rm{40~45℃}\)熔化,\(\rm{48℃}\)分解。下图是有关物质的溶解度曲线:
已知:\(\rm{Na_{2}SO_{3}+ S}\)
\(\rm{Na_{2}S_{2}O_{3}}\),制备\(\rm{Na_{2}S_{2}O_{3}·5H_{2}O}\)的实验流程如下:
\(\rm{(1)}\)过滤时玻璃棒的作用是 ;趁热过滤的原因是 。
\(\rm{(2)}\)结晶的方法是 。
\(\rm{(3)}\)洗涤抽滤后得到的晶体,可采用的洗涤液是 。
\(\rm{A.}\)水 \(\rm{B.}\)饱和\(\rm{NaCl}\)溶液 \(\rm{C.}\)无水乙醇 \(\rm{D.NaOH}\)溶液
\(\rm{(4)}\)工业上制得的\(\rm{Na_{2}S_{2}O_{3}·5H_{2}O}\)产品中可能含有少量的\(\rm{Na_{2}SO_{3}}\)和\(\rm{Na_{2}SO_{4}}\)杂质。为测定产品成分,准确称取\(\rm{1.2600g}\)样品,加入蒸馏水完全溶解后配成溶液。将配成的溶液平均分成两份。向一份溶液中加入适量甲醛溶液预处理\(\rm{(}\)防止\(\rm{Na_{2}SO_{3}}\)与\(\rm{I_{2}}\)反应\(\rm{)}\),然后向其中加入\(\rm{0.0500mol/L}\)的\(\rm{I_{2}}\)溶液,发生反应:\(\rm{2S_{2}O_{3}^{2}ˉ+ I_{2} = S_{4}O_{6}^{2}ˉ+ 2Iˉ}\),当反应恰好完全时,共消耗\(\rm{I_{2}}\)溶液\(\rm{20.00 mL}\)。向另一份溶液中加入足量的稀硫酸溶液,微热至充分反应,使生成的\(\rm{SO_{2}}\)全部逸出,测得\(\rm{SO_{2}}\)在标准状况下体积为\(\rm{56.00mL}\)。
已知:\(\rm{Na_{2}S_{2}O_{3}+H_{2}SO_{4}=Na_{2}SO_{4}+SO_{2}↑+S↓+H_{2}O}\)
\(\rm{Na_{2}SO_{3}+H_{2}SO_{4}=Na_{2}SO_{4}+SO_{2}↑+H_{2}O}\)
\(\rm{(}\)摩尔质量:\(\rm{Na_{2}S_{2}O_{3}·5H_{2}O:248g/mol}\) \(\rm{Na_{2}SO_{3}:126 g/mol}\) \(\rm{Na_{2}SO_{4}:142 g/mol)}\)
\(\rm{①}\) 样品中含有\(\rm{Na_{2}S_{2}O_{3}·5H_{2}O}\)质量分数是 ;
\(\rm{②}\) 通过计算确定样品的成份及各成份的物质的量之比\(\rm{(}\)写出计算过程\(\rm{)}\)。