问题 实验题

某综合实践活动小组到自来水厂进行参观,了解到源水处理成自来水的工艺流程示意图如下:

⑴源水中含Ca2+、Mg2+、HCO3、Cl等,加入CaO后生成Ca(OH)2,进而发生若干复分解反应,试写出其中的一个离子方程式                                              

⑵加入凝聚剂可以除去其中的悬浮固体颗粒,其过程是          。(填写下列各项的序号)①只有物理过程,无化学过程  ②只有化学过程,无物理过程 ③既有化学过程又有物理过程;

FeSO4·7H2O是常用的凝聚剂,加入后,最终生成红褐色胶状沉淀,则这种红褐色胶状沉淀是        。用化学反应方程式表示实验室制备该胶体的方法:                   

⑶通入二氧化碳的目的是                                          

⑷气体A的作用是                                                

⑸下列物质中,          可以作为气体A的代替品。(填写下列各项的序号)

①ClO2         ②浓氨水       ③SO2                   ④浓硫酸

答案

⑴只要写出下列4个离子方程式中的任意一个,即可。

HCO-3+OH-  CO2-3+H2O;Ca2++CO32-+OHCaCO3↓+H2O;

Ca2++2HCO-3+2OH-  CaCO3↓+CO32-+2H2O;

Mg2++2OH-  Mg(OH)2

⑵③;Fe(OH)3      ⑶除去钙离子;调节溶液酸度

⑷杀菌消毒或氧化性          ⑸①

单项选择题
阅读理解

A new study of 8,000 young people in the Journal of Health and Social Behavior shows that although love can make adults live healthily and happily, it is a bad thing for young people. Puppy love (早恋) may bring stress for young people and can lead to depression (忧郁症). The study shows that girls become more depressed than boys, and younger girls are the worst of all.

The possible reason for the connection between love and higher risk of depression for girls is “loss of self”. According to the study, even though boys would say “lose themselves in a romantic relationship”, this “loss of self” is much more likely to lead to depression when it happens to girls. Young girls who have romantic relationships usually like hiding their feelings and opinions. They won’t tell that to their parents.

Dr Marian Kaufman, an expert on young people problems, says 15% to 20% young people will have depression during their growing. Trying romance often causes the depression. She advises kids not to jump into romance too early. During growing up, it is important for young people to build strong friendships and a strong sense of self. She also suggests the parents should encourage their kids to keep close to their friends, attend more interesting school activities and spend enough time with family.

Parents should watch for signs of depression -- eating or mood changes -- and if they see signs from their daughters or sons, they need to give help. The good news is that the connection between romance and depression seems to become weak with age. Love will always make us feel young, but only maturity (成熟) gives us a chance to avoid its bad side effects.

小题1:What’s the main idea of the passage?

A.Puppy love may bring young people depression.

B.Parents should forbid their children’s love.

C.Romance is a two ­ edged sword for adults.

D.Romance is good for young people.小题2:Which of the following is more likely to have depression?

A.Young people who have a strong sense of selfishness.

B.Young boys whose parents watch for their behavior.

C.Young girls who always hide their feelings and opinions.

D.Careless parents whose children are deep in love.小题3:What can be inferred from the passage?

A.Lacking love can lead young people to grow up more quickly.

B.Early love makes young people keep close to their friends and parents.

C.Parents should help their children to be aware of the signs of depression.

D.The older a woman is,the less likely she seems to lose herself in romance.小题4:What’s the author’s attitude towards puppy love?

A.Confused.

B.Disapproving.

C.Disinterested.

D.Scared.