试题与答案

下列说法正确的是[ ] ①活化分子间的碰撞一定能发生化学反应 ②普通分子有时也能

题型:不定项选择题

题目:

下列说法正确的是[ ]

①活化分子间的碰撞一定能发生化学反应

②普通分子有时也能发生有效碰撞

③升高温度会加快反应速率,原因是增加了活化分子的有效碰撞次数

④增大反应物浓度会加快反应速率的原因是单位体积内有效碰撞的次数增多

⑤使用催化剂能提高反应速率,原因是提高了分子的能量,使有效碰撞频率增大

⑥化学反应实质是活化分子有合适取向时的有效碰撞

A.①②⑤ 

B.③④⑥

C.③④⑤⑥ 

D.②③④

答案:

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At London College, the boys can go to the city in the afternoon. But they must return to the school before six. And Bob doesn’t often obey the rule. One afternoon, Bob walked to the city and went to the cinema. When he got to the school, it was eight o’clock. He was a little worried. He ran quickly to the gate. It was closed. He went round the school building to another door. That one was closed, too. Then he saw an open window on the ground floor. It was the head teacher’s office. Bob looked into the room, and no one was there. He quickly climbed up and jumped into the room. Just then he heard a voice. He looked around and hid(藏)under the sofa. One minute later, Mr. Scott, the head teacher, came in. He turned on the light(灯) and sat down on the sofa. Then he began to read. Bob lay under the sofa and looked at the head teacher’s feet for an hour. He could not move. At last the head teacher stood up and walked towards the door. “Thank goodness, he didn’t find me under the sofa.” thought Bob. Then the head teacher stopped. He turned his head and spoke to the sofa, “Would you mind turning off the light when you leave?” he said and left the office.

小题1: Bob got to the school ___________.

A.at eight o’clock in the morning

B.after the given time

C.before the given time

D.on time小题2:Bob went into the head teacher’s___________.

A.office

B.bedroom

C.dining room

D.living room小题3:Bob _________ the sofa.

A.lay under

B.lay on

C.sat on

D.sat under小题4:Bob could see Mr. Scott’s__________.

A.hand

B.bag

C.feet

D.books小题5:Mr.Scott knew that_________________.

A.Bob went to the cinema

B.Bob was in the classroom

C.Bob returned to the school

D.Bob was under the sofa

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