问题 填空题

常温下将0.01molCH3COONa和0.004mol盐酸溶于水,配成0.5L混合溶液.

(1)溶液中共有______种微粒.

(2)溶液中有两种微粒的物质的量之和一定等于0.01mol,它们是______.

(3)溶液中n(CH3COO-)+n(OH-)-n(H+)=______mol.

答案

(1)0.01molCH3COONa和0.002molHCl溶于水得到0.006molCH3COONa、0.004molCH3COOH、0.004molNaCl,CH3COONa、NaCl为强电解质,CH3COOH为弱电解质,

则溶液中存在的离子为:Na+、H+、Cl-、OH-、CH3COO-,存在的分子为:H2O、CH3COOH,即共有7种不同的微粒.

故答案为:7.

(2)根据醋酸根守恒可知,CH3COOH、CH3COO-两种微粒的物质的量之和等于0.01mol.

故答案为:CH3COOH、CH3COO-

(3)根据电荷守恒可知,n(Na+)+n(H+)=n(Cl-)+n(OH-)+n(CH3COO- ),

所以n(CH3COO-)+n(OH-)-n(H+)=n(Na+)-n(Cl-)=0.01mol-0.004mol=0.006mol.

故答案为:0.006.

阅读理解

Reading comprehension.

     A study involving 8, 500 teenagers from all social backgrounds found that most of them are ignorant

when it comes to money. The findings, the first in a series of reports from NatWest that has started a five-

year research project into teenagers and money, arc particularly worrying as this generation of young people

is likely to be burdened with greater debts man any before.

     University tuition fees (学费) are currently capped at £3,000 annually, but this will be reviewed next year

and the Government is under enormous pressure to raise the ceiling.

     In the research, the teenagers were presented with die terms of four different loans but 76 per cent failed

to identify the cheapest. The young people also predicted that they would be earning on average £ 31.000 by

the age of 25, although the average salary for those aged 22 to 29 is just £ 17,815. The teenagers expected

to be in debt when they finished university or training, although half said that they assumed the debts would

be less than £ 10.000. Average debts for graduates are £ 12,363.

     Stephen Moir, head of community investment at the Royal Bank of Scotland Group which owns NatWest,

said. "The more exposed young people are to financial issues, and the younger they become aware of them,

the more likely they arc to become responsible, forward-planning adults who manage their finances confidently

and effectively."

     Ministers are deeply concerned about the financial pressures on teenagers and young people because of

student loans and rising housing costs. They have just introduced new lessons in how to manage debts. Nikki

Fair-weather, aged 15 from St Helens, said that she had benefited from lessons on personal finance, but

admitted that she still had a lot to learn about money.

1. Which of the following can be found from the five-year research project?

A. Students understand personal finances differently.

B. University tuition fees in England have been rising.

C. Teenagers tend to overestimate their future earnings.

D. The students' payback ability has become a major issue.

2. The phrase "to raise the ceiling" in paragraph 2 probably means "______".

A. to raise the student loans

B. to improve the school facilities

C. to increase the upper limit of the tuition

D. to lift the school building roofs

3. According to Stephen Moir, students ______.

A. are too young 10 be exposed 10 financial issues

B. should learn 10 manage their finances well

C. should maintain a positive attitude when facing loans

D. benefit a lot from lessons on personal finance

4. What can we learn from the passage?

A. Many British teenagers do not know money matters well.

B. Teenagers in Britain are heavily burdened with debts.

C. Financial planning is a required course at college.

D. Young people should become responsible adults.

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