题干

在25℃、1.01×105Pa下,将22gCO2通入到750mL 1.0mol·L-1的NaOH溶液中充分反应,放出x kJ热量。在该条件下1molCO2通入到2L 1.0mol·L-1的NaOH溶液中充分反应,放出ykJ热量,则CO2与NaOH反应生成NaHCO3的热化学反应方程式为

A:CO2(g) + NaOH(aq) = NaHCO3(aq)△H=' -' (2y-x) kJ·mol1

B:CO2(g) + NaOH(aq) = NaHCO3(aq)△H=' -' (4x-y) kJ·mol1

C:CO2(g) + NaOH(aq) = NaHCO3(aq)△H=' -' (2x-y) kJ·mol1

D:CO2(g) + NaOH(aq) = NaHCO3(aq)△H=' -' (8x-2y) kJ·mol1

上一题 下一题 0.0难度 选择题 更新时间:2018-01-02 02:06:15

答案(点此获取答案解析)

B

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完形填空。阅读下列短文,从每小题所给的A、B、C、D四个选项中选出一个最佳选项。

    After his parents' meeting , Wang Jiaming , 14 , from Beijing knows that he will face invisible(看不见的)“enemies”—“other excellent students”.

    “Look at such and such a student . You and he are taught by the same teachers . Why couldn' t you be as 1 as him ?”his mother would say .

    Many students hear 2 words from their parents . After the parents' meeting , their parents begin to 3 them with other students , especially those who are praised by teachers .

    “I want to encourage my child to 4 them ,”explained Li Shulan , a mother of a 14-year-old boy from Xi'an , Shanxi .However , many children , like Wang , don' t like it .

    “I feel very 5 and sometimes even‘hate'those students ,”Wang said .Parents have good intentions(意图), but in fact they could 6children's selfesteem(自尊),said Li Ying,a  psychological (心理的) teacher at Xiamen Hubin Middle School in Fujian . If children feel hurt , they should let parents know it .“You can choose a relaxing occasion , for example , over the dinner , and tell your parents your feelings ,”Lin said .“Also , some articles online explain 7 it could be bad for children . You may want to show such articles to your parents .”

    It's not all bad , though . Liu Jiayang , 13 , from Taizhou , Zhejiang said students could take the chance to learn to be open-minded .

    “I find the students that my mom talks about really have strong 8 that I don' t have . I take them as examples and try to 9 with them ,”she said .

    “During the process(过程), always keep in mind that you' re unique(特别的). Never 10 heart ,”Lin added .