问题 实验题

(14分)已知粗铜中含有少量的锌、铁、银、金等金属和少量矿物杂质(杂质与酸不反应)。某化学兴趣小组在实验室条件下以硫酸铜溶液为电解液,用电解的方法实现了粗铜的提纯,并对阳极泥和电解液中金属进行回收和含量测定。

步骤一:电解精制:

电解时,粗铜应与电源的  ▲ _极相连,阴极上的电极反应式为  ▲ 

电解过程中,硫酸铜的浓度会  ▲ (选填:变大、不变、变小)。

步骤二:电解完成后,该小组同学按以下流程对电解液进行处理:

(1)阳极泥的综合利用:

稀硝酸处理阳极泥得到硝酸银稀溶液,请你写出该步反应的离子方程式:  ▲   。残渣含有极少量的黄金。为了回收金,他们查阅了有关资料(见下表):

序号反应化学平衡常数
1Au + 6HNO3(浓) Au(NO3)3 + 3NO2↑+ 3H2O<< 1
2Au3+ + 4Cl- =" " AuCl4->>1
 

从资料中可知,金很难与硝酸反应,但却可溶于王水(浓硝酸与盐酸按体积比1∶3的混合物),请你从化学平衡移动的角度简要解释金能够溶于王水的原因   ▲  

(2)滤液含量的测定:以下是该小组探究滤液的一个实验流程:

则100mL滤液中Cu2+的浓度为  ▲   mol·L-1,Fe2+的浓度为 ▲  mol·L-1

答案

步骤一:正;Cu2+ + 2e- = Cu;变小

步骤二:(1)3Ag + 4H+ +NO3- = 3Ag+ + NO↑+ 2H2O;

王水中的Cl-与Au3+反应,降低了Au3+的浓度,使平衡向正反应方向移动,Au不断溶解

(2)0.5 ;0.1

阅读理解

B

Students’ Insurance

What Is Covered under Contents?

Under the “Contents” section your possessions---which you do not have to be listed---will be protected on “new for old” basis where items will be replaced as new---regardless of their age or condition.

“Contents” include books, radios, audio and video players, TVs, jewellery, home computers, furniture, household goods, other electrical equipment and sports equipment. They will be insured as follows:

Theft

Fire, Lighting, Explosion

Malicious(恶意)Damage

Storm, Flood and other natural disasters

But new-for-old cover does not include clothing and linen.

Where Does Cover Apply?

Anywhere in Australia whether in:

Your Living Place While at College

Your Parents’ Home or Any Temporary Residence(临时住处)---where you are staying when away from College

Your College or Students’ Union Building

College Storage during Vacations

Plus The Following Benefits Included Free

Loss or Damage to:

Gas, water and electricity meters and telephones---up to$300

TVs and videos rented in your name

Library books---up to $300

Daily things bought---up to $500 as to cover described under “Contents”

College or Landlord’s Possessions in your rooms by Fire or Theft (if you are legally responsible---up to $2,000)

Personal Money: from your room---up to $60

PLUS fraudulent(欺诈)use of your Credit Card---up to $1,000

61. If you lose an old video player, the insurance company will _____.

A. replace it with a new one  B. pay you up to $30 in insurance

C. pay you nothing for it is old         D. replace it with a used one

62. Which of the following statements is TRUE according to the passage?

A. Your household goods will not be insured due to natural disasters.

B. Your computer is insured when you are away from college.

C. You can be paid $2,000 for fraudulent use of your Credit Card.

D. Your rented car is completely insured if it is damaged.

63. All of the following are included in the insurance project except _____.

A. audio and video players, TV        B. jewellery, library books

C. clothing, linen and cars             D. furniture, home computers

64. It can be inferred from the passage that _____.

A. if you lose a radio you can get another one

B. if you have your possessions stolen outside Australia they are not insured

C. if a fire breaks out in your room you can get everything back

D. if your jewellery is stolen you will be paid as much as $300 

填空题