题干

如图,在二个圆底烧瓶中都充满NO2气体,并分别放置在加有下列物质的烧杯(烧杯内有水)中:在(1)中加入无水CaCl2,(2)中不加其他任何物质,在(3)中加入NH4Cl晶体。发现:

(1)中红综色变深,(3)中红棕色变浅。下列叙述正确的是(   )

A:CaCl2溶于水时放出热量

B:烧瓶(1)中气体的压强不变

C:NH4Cl溶于水时放出热量

D:烧瓶(3)中气体的压强增大

上一题 下一题 0.0难度 选择题 更新时间:2017-06-08 02:53:36

答案(点此获取答案解析)

A

同类题4

根据短文内容,选择正确答案。

A

    Each New Year is a time for change and a fresh start, so many people like to make New Year's Resolutions(决心). A New Year's Resolution is a promise you make to yourself to do something good or to stop doing something bad in the New Year. Here are some teenagers' New Year's Resolutions for 2016.

    My New Year's Resolution is to get healthy. I'll stop drinking soda, and I'll eat more fruit at least an apple every day. I'll also do more exercise, such as playing basketball for half an hour every day.

Brandon   


    I want to get better grades in the New Year. To realize it, I will pay more attention in class, do homework on time and study hard. When I have difficulties with lessons, I'll ask others for help instead of giving it up.                                                                                                                                                       

Laura


    I would like to be nice to the people around me, and not get angry for every little thing that others say or do to me. When I do feel angry, I'll take a break and find good ways to deal with it like exercising, reading, writing, or talking with a friend or parent.                                                                                                                                         

Jack   


    I'll try to be more helpful to others. I will start with small things, like helping my parents clean the house and wash dishes after meals. I'd also like to volunteer in some places in my community.                                                                                                                                                

Erica