问题 填空题

已知25℃时几种物质的电离度(溶液浓度均为0.1mol/L) 如下表(已知硫酸的第一步电离是完全的):

①硫酸溶液②硫酸氢钠溶液③醋酸溶液④盐酸
HSO4-⇌H++SO42-HSO4-⇌H++SO42-CH3COOH⇌CH3COO-+H+HCl=H++Cl-
10%29%1.33%100%
(1)根据题意,请写出向硫酸溶液中滴加足量氢氧化钡溶液反应的离子反应方程式______

(2)25℃时,0.1mol/L上述几种溶液中C(H+)由大到小的顺序是______(填序号,下同);

(3)25℃时,将足量锌粉放入等体积pH=1的上述几种溶液中,产生H2的体积(相同状况)由大到小的顺序是______;

(4)25℃时,0.1mol/L H2SO4中的HSO4-的电离度小于0.1mol/L NaHSO4中HSO4-的电离度的原因是:______.

答案

(1)硫酸第一步电离出氢离子和硫酸氢根离子,硫酸氢根离子电离较弱,在硫酸溶液中主要以硫酸氢根离子存在,氢氧化钡溶于水电离出的氢氧根离子和氢离子反应促进硫酸氢根离子电离,同时硫酸根离子和钡离子反应生成硫酸钡沉淀,所以离子反应方程式为:H++HSO4-+Ba2++2OH-=BaSO4↓+2H2O,

故答案为:H++HSO4-+Ba2++2OH-=BaSO4+2H2O;

(2)硫酸第一步完全电离,第二步部分电离,硫酸中C(H+)=(0.1+0.1×10%)mol/L=0.11mol/L;

硫酸氢钠溶液中,C(H+)=(0.1×29%)mol/L=0.029mol/L;

醋酸溶液中,C(H+)=(0.1×1.33%)mol/L=0.00133mol/L;

盐酸溶液中,C(H+)=0.1mol/L;

所以C(H+)由大到小的顺序是①④②③,故答案为:①④②③;

(3)等体积pH=1的上述几种溶液中,氢元素的物质的量由大到小的顺序是③②①④,则生成氢气的体积③②①④,

故答案为:③②①④;

(4)硫酸溶液中,硫酸第一步电离出氢离子,第二步又电离出氢离子,第一步电离出的氢离子抑制了第二步的电离,而硫酸氢钠溶液中硫酸氢根离子只有一步电离,所以.1mol/L H2SO4中的HSO4-的电离度小于0.1mol/L NaHSO4中HSO4-的电离度,

故答案为:硫酸的第一步电离抑制了硫酸氢根离子的电离.

阅读理解

阅读理解。

     Sometimes, something that is considered to be negative turns out to be an advantage on the job. Though

he is only l8 years old and blind, Suleyman Gokyigit is among the top computer technicians and programmers

at InteliData Technologies Corp., a large software company with several offices across the United States.

     "After our company united with another one last October, two different computer networks were driving

us crazy," recalls Douglas Braun, the InteliData president. "We couldn't even send e-mail to each other." In

three weeks Mr Gokyigit created the software needed to connect the two networks. "None of the company's

350 other employees could have done the job in three months," says Mr. Braun. "Suleyman can 'see' into the

heart of the computer."

     Mr. Gokyigfi's gift, as Mr. Braun calls it, is an unusual ability to form an idea of the inside of a machine.

"The computer permits me to reach out into the world and do almost anything I want to do," says Mr. Gokyigit.

     The young programmer is at home with hardware as well, thanks partly to a highly developed sense of

touch. Mitzi Nowakowski, an office manager at InteliData, remembers how he easily disconnected and

reconnected their computer systems during a move last year. "Through feel, Suleyman can find the position

of connectors, pins and wires much faster than most other people with sight," he says.

     Much of the student programmer's speed comes from his ability not to be interrupted while at the computer.

When typing, he listens carefully to the synthesizer (合成器). His long, thin fingers fly over the keyboard.

"Nothing seems to shake his attention," says Mrs. Nowakowski, his boss.

     Mr. Gokyigit is the only company employee who is available (可找到的) 24 hours a day. "We consider him

our top problem solver." says Mr. Braun.

1. According to Mr. Braun, Suleyman _____.

A. can work wonders on computer

B. is the best technician in the world

C. has done a hard job in three months

D. has united InteliData Technologies Corp. with another computer company

2. The underlined part "is at home with hardware" (paragraph 4) means _____.

A. is good at dealing with computer hardware

B. is fond of computer hardware

C. works with computer hardware at home

D. feels comfortable when working with computer hardware

3. Suleyman was quick while at the computer mostly because of _____.

A. his blindness

B. his attention on the synthesizer

C. his long, thin fingers

D. his ability not to be interrupted

4. Suleyman was quick while at the computer mostly because of _____.

A. his blindness

B. his attention on the synthesizer

C. his long, thin fingers

D. his ability not to be interrupted

单项选择题 A1型题