问题 实验题

某化学课外小组的同学,在实验室实验时发现一瓶标签破损的无色溶液(如图),这瓶溶液是什么物质?在老师的指导下,同学们首先提出假设并进行了如下的探究活动。请在空白处完成相应内容。

(1)[提出假设]                               

(2)[实验及现象] ①在试管中取少量黑色粉末二氧化锰,向其中滴入该无色溶液,立即产生大量气泡,并放出大量的热。②将气体导出并用排水法收集一试管气体;③检验收集到的气体的方法及现象是                           该无色溶液是                    ,二氧化锰在此实验中起                         作用,反应的文字表达式为                               ,原假设成立。

答案

(1)该无色溶液可能是双氧水

(2)将带火星的木条伸入集气瓶,木条复燃;双氧水;催化;双氧水水 + 氧气

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C

We all love festivals. But since culture develops differently in many places, some festivals are, to us, very strange. Let’s take a look at some unique(独特的)festivals around the world.

Cheese Rolling Festival (England)

The festival started in the 15th century in May. When a round cheese is rolled, competitors run down the hill and try to catch it before it reaches the bottom. As the cheese can reach speeds of up to 112 km/h, it’s rare that someone catches the cheese. First to the bottom wins the cheese. But running down a very steep(陡峭的) hill behind a cheese can be dangerous. Eight people were injured in 1992.

Roswell UFO festival (New Mexico, US)

The Roswell UFO festival celebrates the anniversary(纪念日) of the “Roswell Incident”, when a UFO was said to have crashed(坠毁) nearby. Every year in July, experts, authors, researches and lecturers come to discuss the incident. The celebration also includes an alien parade, an alien costume contest, and an alien hot air balloon ride.

Hemingway Days (Florida, US)

This festival has normal stuff (材料,东西) like short-story readings and exhibits about the author. But the highlight (亮点) of the festival is definitely (一定地) the Hemingway look alike contest.

Imagine walking into a bar and being greeted by 20 middle-aged men who all look alike: stocky with thick white beards. The festival takes place in mid-July every year.

小题1:Which festival takes place in mid-July every year?

A.Cheese Rolling Festival.

B.Roswell UFO festival.

C.Hemingway Days.

D.All of the above.小题2:Which festival may cause injuries according to the passage?

A.Cheese Rolling Festival.

B.Roswell UFO festival.

C.Hemingway Days.

D.None of the above.小题3:Which of the following is right according to the passage?

A.All the three festivals are celebrated in America.

B.It’s common that someone catches the cheese in Cheese Rolling Festival.

C.It’s said that a UFO once crashed in New Mexico, US.

D.In Hemingway Days, you’ll see 20 old or young Hemingways