问题 填空题

pC类似pH,是指极稀溶液中,溶质物质的量浓度的常用对数负值。如某溶液溶质的浓度为:1×10-3mol/L,则该溶液中溶质的pC=-lg(1×10-3)=3。下图为,H2CO3在加入强酸或强碱溶液后,平衡时溶液中三种成分的pC-pH图。请回答下列问题

(1)在人体血液中,HCO3-能起到稳定人体PH的作用,请用电解质溶液中的平衡解释:

_____________________(用方程式表示)。

(2)H2CO3一级电离平衡常数的数值Ka1≈_____________               

(3)某同学认为该溶液中Na2CO3的水解是微弱的,发生水解的CO32-离子不超过其总量的10%。请你设计简单实验证明该同学的观点是否正确_______________。

(4)已知某温度下Li2CO3的Ksp为1.68×10-3,将适量Li2CO3固体溶于100 mL水中至刚好饱和,饱和Li2CO3溶液中c(Li+)=0.15 mol·L-1。c(CO32-)=0.075 mol·L-1若t1时刻在上述体系中加入100 mL0.125 mol·L-1 Na2CO3溶液,列式计算说明是否有沉淀产生。

(5)请画出t1时刻后Li+和CO32-浓度随时间变化关系图(用虚线表示Li,实线表示CO32-)。

答案

(1)HCO3- CO32-+H+、HCO3- H2CO3+OH 

(2)10-6  

(3)用pH试纸(或pH计)测常温下0.1mol·L-1 Na2CO3溶液的pH,若pH<12,则该同学的观点正确;若pH>12,则该同学的观点不正确

(4)c(Li+)=0.075mol/l、c(CO32-)=0.01mol/l,Qc=c(CO32-)·c2(Li+)=5.6×10-5< Ksp,无沉淀

(5)

阅读理解

Over 500 dogs being delivered to a butcher house were saved by a Chinese animal protection organization. The incident then resulted in a debate among Chinese netizens about the necessity of pouring so much money and efforts into saving dogs.

On Friday, a truck loaded with over 500 dogs was stopped by volunteers from animal protection organization on Beijing section of Jingha expressway.

Beijing Times reported these dogs were being delivered to slaughter houses in the city of Changchun, northeast one in Jilin Province and would be eventually served on dinner tables.

After negotiations  (协商)  with the truck driver and a philanthropic  (慈善)  founda tion, Shangshan Foundation purchased these dogs with much money. Dogs were then delivered to the headquarter of China Small Animal Protection Association (CSAPA) , being taken care of and waiting for adoption.

After the dog saving mission was reported, Chinese net users debate over whether saving dogs worth so much efforts and money while there are still many poor and needy people in China lacking assistance.

Some net users argue the dog saving mission is placing too much attention to animals while lots of needy people are still left unattended.

A microblogger "Xiaowulaitajie" said on China's twitter-like website, weibo. com, "Dogs are saved, adopted and they attracted media attention. We'd better spend such money and take such efforts in helping the needy people. "

Another microblogger, Liluping, said "We poured such huge sum of money into saving dogs. I would rather the money be spent on disaster relief. "

Some applaud volunteers' actions and show eagerness of offering their helping hands to those saved dogs.

Still many disapprove those "saving dogs" critics. They argue that such act nevertheless embodies social progress.

A microblogger named "broken bridge" said, saving dogs does not go against taking care of people. Such enthusiasm in public affairs will help raise social awareness in helping the needy.

I think people and animals are created equal. Attention should be paid to people as well as animals.

小题1:. According to the passage, we know the article probably comes from________ .

A.a science fiction

B.a TV programme

C.the Internet

D.a magazine小题2:. Which one has the similar meaning to the underlined word “embodies”?

A.express.

B.share.

C.emphasize.

D.prevent.小题3:. Whose opinion is closest to the writer's?

A.Some net users'.

B.Liluping's.

C. Broken bridge 's.

D. Xiaowulaitajie's.小题4:. What does the passage mainly talk about?

A.Why some people disagree to save the 500 dogs.

B.How the volunteers saved the 500 dogs to be killed.

C.These dogs were finally saved and sent back to their owners.

D.Different Chinese net users have different opinions on the mission.

单项选择题