【单选题】听力原文:W: I've got two tickets for a volleyball match this evening. Why don't you come? M: Uh...no, thanks. I...I'm not very interested in volleyball. W: Oh, why not? Have you ever seen it played? M: No...
A.
Because there are so many very people enjoying.
B.
Because players can build up their body.
C.
Because it is very fast, with lots of action.
D.
Because the volleyball is interesting to watch.
【单选题】甲烷的燃烧反应方程式为: CH 4 +aO2= CO 2 +bH 2 O ,其中 a 、 b 分别为
【单选题】听力原文:Why don't you come with us to dinner on Friday? (A) I didn't bring anyone along. (B) That would be great. (C) I saw one on the dining table. (35)
【单选题】下列热化学方程式中,正确的是( )
A.
甲烷的燃烧热为890.3 kJ?mol -1 ,则甲烷燃烧的热化学方程式可表示为:CH 4 (g)+2O 2 (g)=CO 2 (g)+2H 2 O(g)△H=-890.3 kJ?mol -1
B.
500℃、30MPa下,将0.5mol N 2 和1.5molH 2 置于密闭容器中充分反应生成NH 3 (g),放热19.3 kJ,其热化学方程式为:N 2 (g)+3H 2 (g) 加热 . 2NH 3 (g)△H=-38.6 kJ?mol -1
C.
HCl和NaOH反应的中和热△H=-57.3 kJ?mol -1 ,则H 2 SO 4 和Ca(OH) 2 反应的中和热△H=2×(-57.3)kJ?mol -1
D.
在101 kPa时,2gH 2 完全燃烧生成液态水,放出285.8lkJ热量,氢气燃烧的热化学方程式表示为2H 2 (g)+O 2 (g)=2H 2 O(1)△H=-571.6 kJ?mol -1
【单选题】— Why don't you come and play tennis with us this afternoon? — ______.
【单选题】在间接碘量法中,若酸度过强,则会造成( )。
【单选题】顺序阀的作用是依靠液体()控制阀口通、断,从而控制系统中各执行元件动作先后顺序的压力阀。
【简答题】是用来控制液压系统中各种执行元件动作的先后顺序。A. 顺序阀
【简答题】4-7 有一弹簧,当其下端挂一质量为 m 的物体时,伸长量为9.8 ×10 -2 m.若使物体上、下振动,且规定向下为正方向.(1)当 t =0 时,物体在平衡位置上方8.0 ×10 -2 m处,由静止开始向下运动,求运动方程.(2)当 t =0时,物体在平衡位置并以0.6m·s -1 的速度向上运动,求运动方程.
【单选题】下列热化学方程式中,正确的是
A.
甲烷的燃烧热为890.3 kJ·mol -1 ,则甲烷燃烧的热化学方程式可表示为:CH 4 (g)+2O 2 (g)=CO 2 (g)+2H 2 O(g)△H=-890.3 kJ·mol -1
B.
由N 2 (g)+3H 2 (g) 2NH 3 (g)△H=-92.4 kJ·mol -1 热化学方程式可知, 当反应中转移6N A 电子 时,反应放出的热小于92.4 kJ
C.
HCl和NaOH反应的中和热△H='-57.3' kJ·mol -1 ,则H 2 SO 4 和Ca(OH) 2 反应的中和热△H=2×(-57.3)kJ·mol -1
D.
在101 kPa时,2gH 2 完全燃烧生成液态水,放出285.8kJ热量,氢气燃烧的热化学方程式表示为2H 2 (g)+O 2 (g)=2H 2 O(1)△H=-571.6 kJ·mol -1