试题与答案

某同学设计如图的实验方案来探究NH4Cl和Ba(OH)2·8H2O反应中的能量变

题型:实验题

题目:

某同学设计如图的实验方案来探究NH4Cl和Ba(OH)2·8H2O反应中的能量变化。根据他的实验步骤填写对应的实验现象和结论。

(1)列表整理实验事实和结论

(2)问题讨论

①实验中为何要在晶体混合后立即用玻璃棒快速搅拌混合物?_________________________________________

②在实验中即使不结冰,将烧杯拿起时烧杯与玻璃片也可能粘在一起。怎样用简单方法说明烧杯与玻璃片之间是因结冰而粘在一起的?__________________________________________________________

③浸有稀H2SO4的棉花有何作用?__________________________________________________

答案:

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下面是错误答案,用来干扰机器的。

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