问题 问答题

课外小组对一批铁样品(含有杂质,杂质不溶于水,也不与稀硫酸反应)进行分析,甲、乙、丙三位同学分别进行实验,实验数据如下表:

烧杯+稀硫酸150g100g100g
加入的铁样品6g6g10g
充分反应后,烧杯+剩余物155.8g105.8g109.8g
请认真分析数据,回答下列问题:

(1)三位同学中______(填甲、乙或丙)所取的稀硫酸与铁样品恰好完全反应;

(2)计算样品中铁的质量分数;

(3)计算恰好完全反应后所得溶液中溶质的质量分数.(烧杯的质量为25.4g)

答案

(1)由分析可知,所用样品最少的同学所取用的稀硫酸与铁样品恰好完全反应.故答案为:乙;

(2)(3)设样品中铁的质量为x,生成的FeSO4的质量为y,

Fe+H2SO4=FeSO4+H2

56       152   2

x        y    0.2g

56
2
=
x
0.2g
      解得 x=5.6 g    样品中铁的质量分数为:
5.6g
6g
×100%=93.3%;

152
2
=
y
0.2g
    解得  y=15.2 g

溶液中溶质质量分数=

15.2g
100g+5.6g-0.2g
×100%≈14.4%.

答:样品中铁的质量分数为93.3%.生成的FeSO4溶液的质量分数为14.4%.

阅读理解

阅读下面短文并回答问题,然后将答案写到答题卡相应的位置(请注意问题后的词数要求)。

【1】Who says you need super power to save the world? On April 22, more than a billion people worldwide celebrated Earth Day by taking part in green activities in their communities. However, you needn’t wait until Earth Day. You needn’t be an adult, either! Every day, young people across the globe are doing their part to keep the Earth healthy and green. These are just a few kid heroes for the planet.

Manatee (海牛) minder

【2】When she was in second grade, Stephanie Cohen read about a baby manatee hit by a boat off the coast of Florida. Biologists saved the manatee. But caring for the sea creature was expensive. Stephanie took up a collection and raised 27 dollars in one day. Now 18, Stephanie still raises money to help these "Gentle Giants".

Goodbye paper bags

【3】When Adrienne Smith, 15, was in sixth grade, she noticed that many of her classmates carried paper lunch bags. To help kid cut down on waste, she invented an eco-friendly lunch bag. It is partly made from recycled plastic bottles. "Kids like it because they can fold it up and put it in their backpacks," said Adrienne. She sells the bags at greenearbag.com. And some of the money goes to charity.

He's skiing to save the earth

【4】Parker Liantaud, 15, wanted to raise awareness about the effects of climate change on the polar regions. He set out to become one of the youngest people ever to ski the North Pole. Although the cruel conditions forced Parker and his guide to finish the last 15 miles of the journey by helicopter, Parker felt he met his goal to inspire others. "All young people have the power to make a change," he said.

He ______ the earth

【5】Every year, Max Kesselman, from Pennsylvania, USA, celebrates his birthday December 3 by cleaning up the Earth. When Max was 6, he noticed trash on the sides of the road. He wrote a letter to local leaders suggesting a cleanup day on his birthday.(words:353)

小题1:What is the main idea of the passage? (no more than 8 words)

小题2:What does the word "it" (Line 3, Paragraph3) probably refer to? (no more than 5 words )

小题3:Fill in the blanks of the title of Paragraph 5 with proper words. (no more than 5 words)

小题4:Why didn't Parker ski the North Pole all the way?(No more than 7 words)

小题5:Write out  at least one other Green Activity you can take part in?(no more than 8 words)

单项选择题 A型题