问题 填空题

回答下列问题:

(1)在H、H2、H+中表示氢离子的是______

(2)已知锂(Li)元素的化合价为+1,写出氧化锂的化学式______.

(3)在反应4HNO3

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4NO2↑+2H2O+X↑中,X的化学式为______.

(4)清凉油的主要成分薄荷脑(C10H10O)是由______种元素组成,分子中碳、氢、氧原子个数比为______.

答案

(1)在H、H2、H+中,H表示原子,H2表示氢分子,表示H+离子,原子呈电中性,离子带电荷,故答案为:H+

(2)锂元素的化合价为+1,而氧元素在形成化合物时一般显-2价,根据书写化学式的依据,正价在前,负价在后,十字交叉使化合物中元素化合价的代数和为零,可得锂原子的个数为2,氧原子的个数为1.故答案为:Li2O.

(3)反应物与生成物中原子的种类、数目相同,在4HNO3

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4NO2↑+2H2O+X↑反应中,反应前氢、氮、氧原子的数目分别是:4、4、12个,由质量守恒定律得,反应后的物质中所含的相同原子的数目相等,故可得X中一定含2个氧原子,所以答案为O2

(4)薄荷脑的化学式为C10H10O,根据化学式所表示的意义,宏观上表示该物质由C、H、O三种元素组成,微观上表示构成物质的一个分子中含有10个碳原子、10个氢原子和1个氧原子,所以碳、氢、氧原子的个数比为:10:10:1,故答案为:10:10:1.

所以本题答案为:(1)H+;(2)Li2O;(3)O2;(4)10:10:1.

阅读理解

One night Mr. Lee was driving his wife home from work. She was a staff nurse in a hospital. It was almost midnight and she was quite tired out. She soon fell asleep. Mr Lee looked at her and smiled.

Mr. Lee was a cautious and experienced driver. He knew it was safer to drive slowly on a dark night. After some time he noticed a car following him. It was traveling very fast. Suddenly it overtook his car.

The driver of the car was in a hurry. He did not see the approaching lorry(货车). To avoid hitting it, he swerved his car. It skidded off the road and hit a big tree. The driver and his passenger were injured. They were badly cut by glass splinter from the broken windscreen.

Mr. Lee quickly stopped his car by the side of the road. His wife got out of the car to help the injured men. The lorry driver also stopped to lend a helping hand. Mr. Lee immediately drove off to telephone the police.

About twenty- five minutes later, a police car and an ambulance arrived. The injured men were carried into the ambulance and taken to hospital.

The policemen took down details of the accident. Mr. Lee and the lorry driver told them all that they could remember. The policemen thanked them for their help. Mr. and Mrs. Lee then got into their car and continued their journey home.

小题1:Mrs. Lee fell asleep in the car because_____.

A.she was very tired

B.her husband was driving very slowly

C.it was too late

D.both A and C小题2: When the accident happened, the other car was _____.

A.in front of Lee’s car

B.behind Lee’s car

C.on the right side of Lee’s car

D.on the left side of Lee’s car小题3:To avoid hitting it, the driver swerved his car. "Swerved" means_____.

A stopped suddenly                B. turned to one side

C. drove faster                      D. turned around

填空题