问题 填空题

物质NaClMgCl2AlCl3SiCl4
沸点/℃14651412181(升华)57.6
①从表中的数据,结合学过的化学知识,你能得到的规律是                       

②以上四种物质中,属于共价化合物的是                       

③若你得到的规律具有普遍性,则以下两种物质的沸点高低是:LiCl   BCl3(填“>”、“==”、“<”)。

(2)在密闭容器中,将1.0mol CO与1.0mol H2O混合加热到800℃,发生下列反应:

CO(g)+H2O(g)CO2(g)+H2(g)

一段时间后该反应达到平衡,测得CO的物质的量为0.5mol。

回答下列问题:

①平衡时CO的转化率为           ,该反应的化学平衡常数为           

②如果继续向该平衡体系中通入1.0mol的H2O(g),相同条件下反应达到新的平衡状态,则CO的转化率将            (填“增大”、“减小”、“不变”),预计CO的转化率为         

③427℃时该反应的平衡常数为9.4,请结合①中的计算结果判断该反应的△H   0(填“>”、“==”、“<”)。

答案

(1)①第三周期元素的氯化物,自钠到硅,键型由离子化合物过渡到共价化合物,沸点显著地降低。(2分) ②SiCl4、AlCl3(2分) ③﹥(1分)

(2)①50%(1分),1(1分)②增大(1分),66.7%(或0.667)(2分)③﹤(1分)

(1)①从表中数据可以看出它们的沸点依次降低,且前面两种物质的沸点远高于后面两种,由晶体结构的有关知识可知,它们应属于不同的晶体类型,前两个为典型的金属与典型的非金属形成的化合物,应为离子化合物,属于离子晶体,所以沸点较高;后两者沸点很低只能是属于分子晶体,是共价化合物;所以可得出的规律是:第三周期元素的氯化物,自钠到硅,键型由离子化合物过渡到共价化合物,沸点显著地降低。②由前面分析可知为SiCl4、AlCl3共价化合物;③从上面的规律可知排在周期表左边的氯化物的沸点比在右边的要高,而Li在B的左边,故LiCl >BCl3

(2)①  CO(g)+H2O(g)CO2(g)+H2(g)

开始:    1        1              0       0

转化:    0.5      0.5              0.5      0.5

平衡:  0.5      0.5              0.5      0.5

平衡时CO的转化率为:50%,又因为平衡时各物质的浓度相等,故平衡常数为1。

②增大一种反应物的浓度可以提高其它反应物的转化率而自己本身的转化率要降低,故如果继续向该平衡体系中通入1.0mol的水,CO的转化率将增大。

CO(g)+H2O(g)CO2(g)+H2(g)

开始:     1        2              0        0

转化:     n        n              n        n

平衡:   1—n      2—n            n        n

K=n×n/(1—n)(2—n)="1    " 所以n="2/3     " 故CO的转化率为66.7%

③由800℃变到427℃,平衡常数由1增大到9.4,故降温平衡向正反应方向移动,

所以△H<0.

阅读理解
阅读下面短文,根据短文内容,补全表格中所缺的信息。每空最多填写三个单词。
The idea of Mother’s Day is a very old idea. It was started by the ancient Egyptians (埃及人),who celebrated(庆祝) a day to honor (向……表示敬意) Isis, the mother of the pharaohs. The early Christians(基督教徒) celebrated a day to honor Mary, the mother of Jesus.
Later, English Christians celebrated to honor all mothers. This English holiday was called “Mothering Sunday”. When the English came to America, they did not have time for Mothering Sunday, so the holiday was not celebrated in America. In 1914,the U.S passed a law which designated(规定) the second Sunday in May as Mother’s Day to honor the mothers who had lost sons in war.
Today, Mother’s Day is celebrated in many other countries for all mothers. In Canada, Australia, New Zealand, Mother’s Day is celebrated on the same day as in the United States—the second Sunday in May. Children give their mothers cards, gifts, and flowers. Schools plan Mother’s Day’s special activities.
In China, the holiday is celebrated to show the respect(尊重) the Chinese have for the old people, and the love they have for their parents. Ten top mothers are chosen by the government. People all over the country try different ways to help mothers who are poor.
小题1:_______________________
 
People/County
Who to Honor
Activities
in ancient times
Egyptians
Isis
 
early Christians
Mary
 
later
the English
all mothers
 
the U.S
mothers who had lost sons in war
小题2:_______________
now
Canada, Australia, etc
all mothers
give mothers cards, gifts, and flowers; 小题3:____________
China
小题4:_____________;
parents
choose ten top mothers;
小题5:_______________
单项选择题