问题 填空题

硬水中含有较多可溶性的钙、镁的化合物,其钙的化合物为Ca(HCO32.受热易分解,对其加热生成水和大量气体,还有一种难溶性的盐,该盐是水垢的成分之一.

(1)[提出问题]探究Ca(HCO32受热分解的另外两种生成物

(2)[猜想]①小刚认为生成物中的气体可能是二氧化碳;

②你认为生成物中的固体可能是______.

(3)[设计实验方案]请你设计出简单的实验方案,来验证上述2个猜想是否正确.

①(只要求写出实验步骤)
②(只要求写出实验步骤)
(4)[现象与结论]如果小刚的猜想正确,现象应该是______.

如果你的猜想正确,现象应该是______,

该反应的化学方程式为______.

(5)写出Ca(HC032受热分解的化学方程式______.

答案

(2)②在化学反应前后元素的种类不变,反应前有钙、碳、氢、氧元素,生成物是水垢的主要成分之一,只能是碳酸钙,故答案为:碳酸钙;

(3)检验二氧化碳一般用石灰水,检验碳酸钙一般加入盐酸后生成的气体,

 ①将加热碳酸氢钙产生的气体通入澄清石灰水中
 ②取反应后的固体加水溶解,再加入过量的稀盐酸,将生成的气体通入澄清石灰水中.
(4)二氧化碳会与氢氧化钙生成碳酸钙沉淀,

碳酸钙难溶于水,会溶于盐酸反应生成使澄清石灰水变浑浊的气体二氧化碳,

碳酸钙和盐酸反应生成氯化钙、水和二氧化碳,

故答案为:澄清石灰水变浑浊;反应后的固体不溶于水,但能溶于盐酸,并有气泡冒出,该气体能使澄清石灰水变浑浊.CaCO3+2HCl═CaCl2+H2O+CO2↑;

(5)碳酸氢钙分解会生成碳酸钙、水和二氧化碳,故答案为:Ca(HCO32

  △  
.
 
CaCO3+H2O+CO2

阅读理解

There is a problem each of us faces in following advice on emotional healing: apologizing is difficult. We are trapped in what we think of ourselves by holding onto our pride. We can be selfish and not willing to admit our most obvious mistakes. Pride eats away at us as we argue or ignore the mistake.

It's happened to me. I have had too much pride and selfishness to apologize to a loved one I hurt. When I did want to apologize, I couldn't bring myself to face the other person. This is the pride I'm talking about. Maybe apologies come difficult for men because they're expected to be dominant. It's like the joke that a man never asks for directions when lost. Ladies are more emotionally open than guys and are willing to express it. Still, both genders wonder how to correctly apologize.

In shifting the focus on apologizing away from you, what does not apologizing do to other people? They feel hurt that you are not willing to communicate your mistake. They lose trust in you as you hide behind your mistake avoiding reality. They become angry with you, wondering why you do not tell them the truth. They may begin to counter your lack of apologies by not apologizing themselves and from this the relationship goes downhill as the two of you get caught in a power struggle.

You need to communicate your mistakes. A mistake you made is like a scratch and by not apologizing you are making the scratch a deeper wound and rubbing salt into it. You need to stop hurting the other person and yourself by learning to apologize. There is real power in apologizing and emotional healing.

小题1:Why are men more unwilling to make apologies?

A.They don't intend to hurt other people.

B.They expect others to forgive them.

C.They don't want to be considered weak.

D.They aren't good at expressing themselves.小题2:What bad effect will there be if you refuse to apologize for your mistakes?

A.Other people won't pay attention to you.

B.You will lose confidence in yourself.

C.You won't be forgiven even if you tell the truth.

D.The friendship will get hurt and go worse.小题3:From the last paragraph, it can be inferred that              .

A.communication can stop you making mistakes

B.mistakes would turn into deeper scratches

C.apologizing is good for you and other people

D.apologizing is the most powerful in emotional healing

判断题