将O2和NH3的混合气体448mL通过加热的三氧化二铬，充分反应后，再通过足量的水，最终收集到44.8mL气体。原混合气体中O2的体积可能是（假设氨全部被氧化；气体体积均已换算成标准状况）_刷题宝

题干

将O₂和NH₃的混合气体448mL通过加热的三氧化二铬，充分反应后，再通过足量的水，最终收集到44.8mL气体。原混合气体中O₂的体积可能是（假设氨全部被氧化；气体体积均已换算成标准状况）（）

A：231.5mL

B：268.8mL

C：287.5mL

D：313.6mL

上一题下一题 0.0难度选择题更新时间:2020-02-16 06:15:44

答案(点此获取答案解析）

B,D

同类题1

如图，在Rt△ABC中，∠C=90°，CD是AB边上的中线，且CD=5，则△ABC的中位线EF的长是____

同类题2

This math problem is too difficult. Can you show me________, George?

同类题3

4米5厘米=4.5米

同类题4

根据短文理解，从A、B、C、D四个选项中选择最佳答案填空。

I had a wonderful time with my exchangeprogram(交流活动中心) in France. It's much 1 than I thought. I felt a little nervous before I reached France, but there wasn't any reason to be so. My host 2 is really nice.

They managed various ways to make me 3 at home. Every day I 4 practicing 5 French, I wouldn't believe how 6 progress I 7 in French! Although I still make some mistakes, I can think something in French without

8 everything into Chinese like I used to. My biggest challenge is learning how to behave at dinner table. All the things are really different 9 the way they are at home. You are not supposed to eat anything with your hands except bread. Another thing is that 10 is very rude to say “I'm full now.” you should say “It is delicious." instead.

同类题5

以下说法中正确的是（）

小学学科试题库

初中学科试题库

高中学科试题库