问题 填空题

A是一种白色难溶于水的钙盐,由三种元素组成,其式量为100.

(1)用化学式表示:A______,B______

(2)写出A与盐酸反应的化学方程式:______

(3)D中含有的溶质可能有哪几种情况?______.

答案

(1)A为相对分子质量为100的难溶性钙盐,我们可以初步推断A为碳酸钙,而A在高温煅烧时生成了能和石灰水反应生成A的物质,故可以判断C为二氧化碳,那么A就是碳酸钙,验证了我们的推测,从而可以得出B为氧化钙,故本题答案为:CaCO3;  CaO

(2)已经判断出A为碳酸钙,可以直接写出A与稀盐酸的反应的化学方程式,故本题答案为:CaCO3+2HCl═CaCl2+H2O+CO2

(3)根据(2)的分析可知B为氧化钙,当氧化钙遇到碳酸钠溶液时,要和水反应生成氢氧化钙,然后氢氧化钙和碳酸钠反应,根据氧化钙和碳酸钠溶液的量可以推测无色溶液D的可能组合为:氢氧化钠; 氢氧化钠和碳酸钠;  氢氧化钠和氢氧化钙,故本题答案为:NaOH; NaOH和Na2CO3;NaOH和Ca(OH)2

解答题
阅读理解

根据短文内容,从短文后的选项中选出能填入空白处的最佳选项。选项中有两项为多余选项。

I can’t count the times I called my sister and said, “____2____” She would gasp and stammer(结结巴巴): “I can’t. I have clothes on the line. My hair is dirty. I wish I had known yesterday. I had a late breakfast. It looks like rain.” And my personal favorite response: “It’s just Monday.” She died a few years ago. We never did have lunch together. From then on, I’ve tried to be a little more flexible.

___3__The days get shorter, and the list of promise made to ourselves gets longer. One morning, we are awoken, and all having to show for our lives is repetition of “ I’m going to”, “ I plan on” and “someday, when things are settled down a bit.”

When anyone calls my “seize the moment” friend, she is open to adventure and available for trip. She keeps an open mind on new ideas. Her enthusiasm for life is contagious.___4___My lips have not touched ice cream for 10 years. I love ice cream. The other day, I stopped the car and bought a triple-decker. If my car had hit an iceberg on the way home, I would have died happy.

___5___Do something you want to….., not something on your SHOULD DO LIST.

A.Now go on and have a nice day.

B.Just possible, she may be the wisest woman on this planet.

C.Life has a way of going faster as we get older.

D.So I won’t feel sorry because I have changed my attitude to life.E. How about going to lunch in half an hour?

F. She used to promise to do something instead of doing it right away.

G. You talk with her for a while and you’re ready to change your attitude to life.