防止冷却水进入高压设备,主要是减少()进入高压设备,降低高压设备列管的腐蚀。
参考答案:CL-
防止冷却水进入高压设备,主要是减少()进入高压设备,降低高压设备列管的腐蚀。
参考答案:CL-
化肥是农业生产最基础而且是最重要的物质投入.工业上利用N2和H2合成氨,其化学方程式为:N2(g)+3H2(g)⇌2NH3(g)△H<0
(1)下表为不同温度下该反应的平衡常数.由此可推知,表中T1______573K(填“>”、“<”或“=”).
T/K | T1 | 573 | T2 |
K | 1.00×107 | 2.45×105 | 1.88×103 |
①下列措施中可提高氢气的转化率的有______(填字母).
A.升高温度 B.使用催化剂
C.增大压强 D.循环利用和不断补充氮气
②在一定温度和压强下,将H2和N2按体积比3:1在密闭容器中混合,当该反应达到平衡时,测得平衡混合气中NH3的体积分数为
,此时N2的转化率为______.1 7
(3)某厂每天产生600m3含氨废水(NH3 的浓度为153mg•L-1,废氨水密度为1g•cm-3).该厂处理废水的方法:将废水加热得到NH3,使废水中NH3的浓度降为17mg•L-1.再对加热蒸发得到的NH3用一定量空气氧化.发生的主反应如下:
4NH3+5O2
4NO+6H2O 4NO+3O2+2H2O=4HNO3 一定条件 .
副反应为:4NH3+3O2=2N2+6H2O
①该厂每天通过加热蒸发可得到NH3的物质的量是多少?
②若氧化过程中90% NH3转化为硝酸,10% NH3发生了副反应,则该厂每天消耗标准状况下的空气多少立方米?(假设废水加热前后的体积和密度近似认为不变,空气中氧气的体积分数20%.)
这是某学校通过校长意见箱收集到的一学生的意见和建议。请阅读下文,根据所提的信息,完成下列表格。
Zhang Hongying,girl, 15 I want to make our lunch time longer. At the moment,lunch time is short.Most of my classmates would like to do their homework during this time. But if they don’t get a good rest, they won’t have enough energy for the afternoon. So 1 would like to have more time and have time to take a nap(午睡)after lunch. That way, we’ll learn better in the afternoon. |
Zhao Pengran, girl, 15 I would like to have more chances to talk in English. Now, the English classes are not enough for us to practice spoken English. I think we’d better have one morning a week at least to have spoken English lessons in order to improve our English. |
Zhou Jiancheng, boy, 15 My idea would be to have more fashionable school uniforms. If I were the headmaster, I would ask the students to design the uniforms themselves. We could have a contest among student designers. Then, we could ask others to choose their favorites. This way, we’ll be able to wear what we like best. How nice it would be for us young people! |
Information Card
What would Zhao Pengran like to do in order to improve Englishi | 1.() |
What’s Zhou Jiancheng’s idea | 2.() |
What would Zhang Hongying like to do after lunch | 3.() |
What do most students do during lunch time | 4.() |
How old are the students | 5.() |
第(4)空应()