问题 填空题

请根据如图装置图,回答有关问题:

(1)实验室用B、C装置制取氧气的化学方程式为______.

(2)实验室用高锰酸钾制取氧气,可选用的发生装置是______(填字母).

(3)实验室收集氢气可用D或E装置原因分别是______、______.

答案

(1)实验室用B装置制取氧气不需要加热,应该是利用过氧化氢分解制取氧气,过氧化氢在二氧化锰的催化作用下分解的化学方程式为:2H2O2

MnO2
.
2H2O+O2↑.

故填:2H2O2

MnO2
.
2H2O+O2↑.

(2)实验室用高锰酸钾制取氧气需要加热,可选用的发生装置是A装置.

故填:A.

(3)实验室收集氢气可用D或E装置的原因是氢气的密度比空气小,难溶于水.

故填:氢气密度比空气小;氢气难溶于水.

阅读理解

阅读理解。

     Pit-a-pat. Pit-a-pat. It's raining. "I want to go outside and play, Mum," Robbie says, "When can the rain

stop?" His mum doesn't know what to say. She hopes the rain can stop, too. "You can watch TV with me,"

she says. "No, I just want to go outside." "①Put on your raincoat." "Does it stop raining?" "No, but you can

go outside and play in the rain. Do you like that?" "Yes, mum." He runs to his bedroom and puts on his red

raincoat. "Here you go. Go outside and play." Mum opens the door and says. Robbie runs into the rain. Water

goes ②here and there. Robbie's mum watches her son. He is having so much fun. "Mum, come and play with

me!" Robbie calls. The door opens and his mum walks out. She is in her yellow raincoat. Mother and son are

out in the rain for a long time. They play all kinds of games in the rain.

1. What does Robbie want to do on the rainy day?

A. Help his mother.

B. Watch TV.

C. Wear his raincoat.

D. Go out.

2. What does the underlined phrase (短语) mean in Chinese?

A. ①放上②到处

B. ①穿上②这里和那里

C. ①穿上②到处

D. ①放上②这里和那里

3. Robbie has a _____ day that day.

A. happy

B. scary

C. dangerous

D. boring

4. Which of the following is TRUE according to the passage?

A. The raincoat can stop the rain.

B. Robbie's mum doesn't wear a raincoat in the rain.

C. Robbie first watches TV with his Mum

D. The color of Robbie's raincoat is red.

5. Which is the best title(标题)for the passage?

A. It's raining

B. Fun in the rain

C. Robbie and His mother

D. Robbie's raincoat

单项选择题