试题与答案

(7分)在化学兴趣小组活动中,一标有“生石灰干燥剂”的小纸袋引起了同学们的兴趣。

题型:问答题

题目:

(7分)在化学兴趣小组活动中,一标有“生石灰干燥剂”的小纸袋引起了同学们的兴趣。请你和化学兴趣小组的同学们一起去探究:

【实验探究一】取足量样品于小烧杯中,加适量水,触摸杯壁,无热感。根据上述实验(假如实验过程中无热量散失),你认为此干燥剂       (填“没有”“部分"或“全部")变质。 .

【实验探究--]确定变质的干燥剂成分。

【做出猜想】猜想一:变质的干燥剂成分是氢氧化钙。

猜想二:变质的干燥剂成分是       

猜想三:变质的干燥剂成分是       

【验证猜想】小宁设计的实验方案:取适量样品加入试管中,加水振荡后静置,下层有不溶物,上层清液中滴入酚酞溶液,溶液变红,则变质的干燥剂成分是氢氧化钙。同学们经过认真讨论后一致认为小宁的实验方案不合理,你认为不合理的理由是       。请你在猜想二和猜想三中选择任一猜想设计实验进行探究,完成下面的实验报告:

   实验操作   实验现象   实验结论
   
 

答案:

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