问题 填空题

(14分)根据下图所示的转化关系填空(假设每一步反应的反应物均恰好反应完)

(1)写出反应①的化学方程式:                                         

此反应中,氧化剂与还原剂的个数比为              。当有3.2 g气体产生时,消耗淡黄色固体的物质的量是_______mol,固体增重_______g;

(2)写出反应②、③、④的离子方程式:

                                                 

                                                 

                                                 

答案

(1)2Na2O2+2CO2=2Na2CO3+O2;   1︰1;  0.2,  5.6;

(2)CuO+2H+=Cu2++H2O   Ca2++CO32-=CaCO3↓   Cu2++2OH-=Cu(OH)2

题目分析:能和CO2反应的淡黄色粉末应该是过氧化钠。过氧化钠和CO2反应生成氧气和碳酸钠。碳酸钠和澄清的石灰水反应生成碳酸钙白色沉淀和氢氧化钠。根据反应②生成的是蓝色溶液可知,该溶液中含有铜离子,所以单质是铜,黑色固体是氧化铜。氧化铜和盐酸反应生成氯化铜,氯化铜和氢氧化钠反应生成蓝色沉淀氢氧化铜。

点评:该题是高考中的常见题型,属于中等难度的试题,试题基础性强,难度不大,学生不难得分。解框图题的关键的是寻找“突破口”,“突破口”就是抓“特”字,例如特殊颜色、特殊状态、特殊气味、特殊反应、特殊现象、特殊制法、特殊用途等。

阅读理解

阅读短文,并根据短文内容回答问题。

     A terrible explosive noise was heard, immediately followed by strong shaking of the classroom building.

Mrs Li Lan, a country school teacher in Sichuan, who was giving a class, could hardly keep on her feet,

and many of her pupils made panic cries. Mrs Li realized at once that it must be a powerful earthquake

hitting the area. Although she herself was scared, she managed (设法) to make the children calm down,

opened the door right away and told the children to leave the classroom and get down to the playground

as quickly as possible.

     When all the children had left, she followed them to the first floor. The earth still kept moving

violently (剧烈地). Some of the buildings nearby were falling down, and a great number of falling stones

were rolling down from the hills behind the school. Suddenly, she found a little boy fell over and was hit

by a big stone right on his body. She forgot the danger she was facing and ran over, trying to push the

stone away. The stone was so big that it was not easy for her to move it. She kept pushing until the boy

was pulled out, carrying him to the center of the playground. The boy was later sent to hospital and

saved.

1. What kind of disaster (灾难) happened in the story?

________________________________________________________

2. What was Mrs Li's action when she saw the boy under the stone?

________________________________________________________

3. Did Mrs Li fear death in the face of great danger?

________________________________________________________

4. What do you want to say after you finish reading the story?

________________________________________________________

实验题