问题 推断题

(9分)氯化钡是一种可溶性重金属盐,广泛应用于化工领域,用毒重石(主要成分为BaCO3)制备氯化钡晶体工艺流程如下:

(1)毒重石要进行粉碎的目的是           ;气体X的化学式为        。

(2)滤渣是废弃物,水洗的目的是        ;检验滤渣是否洗净的试剂若是用碳酸钠溶液,则利用的反应的化学方程式为          ;试剂若是用硝酸银溶液 ,则可能生成的沉淀的化学式为             ,此沉淀的直接来源可能有      个。  

(3)操作Y的名称是          ,滤液2中可循环利用的物质除水外还有         

(4)洗涤氯化钡制品最适宜的洗涤剂是    。(填字母)

A.30℃水      B.30℃饱和氯化钠溶液       C.30℃饱和氯化钡溶液

答案

(1)增大反应物的接触面积,加快反应的进行     CO2   

(2)防止钡离子污染环境或提高毒重石的利用率  Na2CO3+BaCl2==BaCO3↓+2NaCl AgCl  2(3)降温结晶      BaCl2   (4)C

题目分析:(1)毒重石要进行粉碎的目的是:增大反应物的接触面积,加快反应的进行,气体X是BaCO3与稀盐酸反应生成的,所以X的化学式为CO2

(2)经过过滤后得到滤渣,表面可能含有BaCl2,所以水洗的目的是防止钡离子污染环境或提高毒重石的利用率;检验滤渣是否洗净的试剂,实际上就是检验溶液中是不是还含有BaCl2,所以用碳酸钠溶液来检验,发生反应的化学方程式为:Na2CO3+BaCl2==BaCO3↓+2NaCl,试剂若是用硝酸银溶液 ,则发生的反应可能是:BaCl2+2AgNO3==2AgCl↓+Ba(NO3)2,所以可能生成的沉淀的化学式为AgCl,也可能是过量的盐酸与硝酸银溶液反应生成的,故此沉淀的直接来源可能有2个

(3)经过操作Y,BaCl2溶液结晶析出BaCl2,故该操作应该是降温结晶,滤液2中可循环利用的物质除水外还有BaCl2

(4)洗涤氯化钡制品最适宜的洗涤剂是30℃饱和氯化钡溶液,这样就不会减少氯化钡的量。故选C3、BaCl2等的化学性质

完形填空
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