问题 多选题

在下列各组实验方案中,不能实现的是(  )

A.KMnO4

O2
点燃
SO3

B.CaCO3

高温
CaO
H2O
Ca(OH)2
K2CO3
CaCO3

C.Cu

o2
CuO
H2O
Cu(OH)2
H2SO4
CuSO4

D.Fe

O2
点燃
Fe3O4
H2
Fe
稀HCl
FeCl2

答案

A、高锰酸钾分解可以制得氧气,但硫在氧气中燃烧生成二氧化硫,不能生成三氧化硫,故符合题意;

B、碳酸钙在高温下即可分解生成氧化钙,氧化钙与水化合可以生成氢氧化钙,氢氧化钙可与碳酸钾反应生成碳酸钙;故B可以实现;不符合题意;

C、铜与氧气能反应生成氧化铜,但氧化铜与水不反应,故不能实现,符合题意;

D、铁在氧气中燃烧生成四氧化三铁,氢气还原四氧化三铁生成铁,铁与稀盐酸能反应生成氯化亚铁,能实验,不符合题意.

故选AC

单项选择题 A1/A2型题
阅读理解

LONDON(Reuters)-Organic fruit, delivered right to the doorstep. That is what Gabriel Gold prefers, and he is willing to pay for it. If this is not possible, the 26-year-old computer technician will spend the extra money at the supermarket to buy organic food.

"Organic produce is always better," Gold said. "The food is free of pesticides(农药), and you are generally supporting family farms instead of large farms. And more often than not it is locally(本地)grown and seasonal, so it is more tasty. "Gold is one of a growing number of shoppers buying into the organic trend, and supermarkets across Britain are counting on more like him as they grow their organic food business. But how many shoppers really know what they are getting, and why are they willing to pay a higher price for organic produce? Market research shows that Gold and others who buy organic food can generally give clear reasons for their preferences-but their knowledge of organic food is far from complete. For example, small amounts of pesticides can be used on organic products. And about three quarters of organic food in Britain is not local but imported(进口)to meet growing demand. "The demand for organic food is increasing by about one third every year, so it is a very fast-growing market," said Sue Flock, a specialist in this line of business.

60. More and more people in Britain are buying organic food because ____.

  A. they are getting richer

  B. they can get the food anywhere

  C. they consider the food free of pollution

  D. they like home-grown fruit

61.Which of the following statements is true to the facts about most organic produce sold in Britain?

  A. It grows indoors all year round.

  B. It is produced outside Britain.

  C. It is grown on family farms.

  D. It is produced on large farms.

62.What is the meaning of "the organic trend" as the words are used in the text?

  A. growing interest in organic food

  B. better quality of organic food

  C. rising market for organic food

  D. higher prices of organic food

63.What is the best title for this news story?

  A. Organic food-healthy, or just for the wealthy?

  B. The making of organic food in Britain

  C. Organic food-to import or not?

D. Good qualities of organic food