问题 选择题

现有下列各组溶液:

①10℃时10 mL 0.1 mol·L-1的Na2S2O3溶液和50 mL0.05 mol·L-1的H2SO4溶液;

②10℃时10 mL 0.05 mol·L-1的Na2S2O3溶液和10 mL 0.1 mol·L-1的H2SO4溶液;

③30℃时10 mL 0.05 mol·L-1的Na2S2O3溶液和10 mL 0.1 mol·L-1的H2SO4溶液。

若同时将它们混合发生反应:Na2S2O3+H2SO4=Na2SO4+S↓+SO2↑+H2O,则出现浑浊的先后顺序是(  )

A.①②③

B.②①③

C.③②①

D.①③②

答案

答案:C

温度越高,反应速率越快,③的反应速率最大;相同温度下,②混合液中Na2S2O3和H2SO4的浓度大于①,故反应速率②>①。

阅读理解

GUATEMALA CITY(Reuters)— A fish that lives in mangrove swamps(红树沼泽)across the Americas can live out of water for months at a time, similar to how animals adapted(适应)to land millions of years ago, a new study shows.

The Mangrove Rivulus, a type of small killifish, lives in small pools of water in a certain type of empty nut or even old beer cans in the mangrove swamps of Belize, the United States and Brazil. When their living place dries up, they live on the land in logs(圆木), said Scott Taylor, a researcher at the Brevard Endangered Lands Program in Florida.

The fish, whose scientific name is Rivulus marmoratus, can grow as large as three inches. They group together in logs and breathe air through their skin until they can find water again.

The new scientific discovery came after a trip to Belize.

“We kicked over a log and the fish just came crowding out.” Taylor told Reuters in neighboring Guatemala by telephone. He said he will make his study on the fish known to the public in an American magazine early next year.

In lab tests, Taylor said he found the fish can live up to 66 days out of water without eating.

Some other fish can live out of water for a short period of time. The walking catfish found in Southeast Asia can stay on land for hours at a time, while lungfish found in Australia, Africa and South America can live out of water, but only in an inactive state. But no other known fish can be out of water as long as the Mangrove Rivulus and remain active, according to Patricia Wright, a biologist at Canada’s University of Guelph.

Further studies of the fish may tell how animals changed over time.

“These animals live in conditions similar to those that existed millions of years ago, when animals began making the transition(过渡)from water onto land,” Wright said.

小题1:The Mangrove Rivulus is a type of fish that__________.

A.like eating nuts

B.prefers living in dry places

C.is the longest living fish on earth

D.can stay alive for two months out of water小题2:Who will write up a report on Mangrove Rivulus?

A.Patricia Wright

B.Researchers in Guatemala

C.Scientists from Belize

D.Scott Taylor小题3:According to the text, lungfish can__________.

A.breathe through its skin

B.move freely on dry land

C.remain alive out of water

D.be as active on land as in waster小题4:What can we say about the discovery of Mangrove Rivulus?

A.It was made quite by accident

B.It was based on a lab test of sea life

C.It was supported by an American magazine

D.It was helped by Patricia Wright

多项选择题