一定条件下，分别向容积固定的密闭容器中充入A和足量B，发生反应_爱下问搜题

搜题请搜索小程序“爱下问搜题”

问题选择题

一定条件下，分别向容积固定的密闭容器中充入A和足量B，发生反应如下：2A(g)+B(s)2D(g)△H＜0,测得相关数据如下，分析可知下列说法不正确的是

	实验Ⅰ	实验Ⅱ	实验Ⅲ
反应温度/℃	800	800	850
c(A)_起始/mol·L^－1	1	2	1
c(A)_平衡/mol·L^－1	.0.5	1	0.85
放出的热量/kJ	a	b	c

A.实验III的化学平衡常数K＜1

B.实验放出的热量关系为b＞2a

C.实验III在30min达到平衡时的速率v(A)为0.005mol• L^-¹·min^-1

D.当容器内气体密度不随时间而变化时上述反应达到平衡

答案

答案：B

题目分析：A、 2A(g)+B(s)2D(g)

起始浓度（mol/L） 1 0

转化浓度（mol/L） 0.15 0.15

平衡浓度（mol/L） 0.85 0.15

所以该温度下反应的平衡常数K＝＝＜1，因此A正确；

B、由于反应前后体积不变，所以实验I和实验Ⅱ的平衡是等效的，因此b＝2a，B不正确；C、实验III在30min达到平衡时的速率v(A)＝＝0.005mol• L^-¹·min^-1，C正确；D、密度是混合气的质量和容器容积的比值，在反应过程中质量是变化的，而容器容积是不变的，因此当容器内气体密度不随时间而变化时上述反应达到平衡，D正确，答案选B。

完形填空

These days，cars are designed using computers．Let’s look at how a new car is created．
First，several   16  talk about the new car and any good ideas that they have．Then they sit down at their computers and   17  many sketches．The best two or three drawings are chosen and then more detailed drawings of   18  are developed on the computer．You can change the size，shape or color of any part on the computer to see   19  the car would look and then you can choose the best design．
Both the inside and the outside of the car have to be designed．Part of the inside of the car is    20 so that the designers can sit in it．They can feel if there is enough 21 inside and if they can reach 22 ．Then some cars are built-there are more than 15，000 parts of a car to 23 ．
When everything is known to be   24  ，the cars are made in the factory．Again，computers are used to make sure that all the parts are   25  as they are needed．The factory
usually stays open all through the night so that the car production never stops．

C．comfortable

选择题

我们在日常生活中都要食用碘盐，许多人喜欢购买增铁酱油、高钙牛奶、富硒茶叶等。这里的碘、铁、钙、硒指的是

A．元素

B．单质

C．原子

D．化合物