题干

温度为T时,向V L的密闭容器中充入一定量的A和B,发生反应:A(g)+B(g)⇌C(s)+xD(g)△H>0,容器中A、B、D的物质的量浓度随时间的变化如图所示,下列说法不正确的是(  )

A:反应在前10min的平均反应速率v(B)=0.15mol/(L•min)

B:该反应的平衡常数表达式K= c2(D)c(A)c(B)

C:若平衡时保持温度不变,压缩容器体积平衡向逆反应方向移动

D:反应至15min时,改变的反应条件是降低温度

上一题 下一题 0.0难度 选择题 更新时间:2017-02-19 03:38:32

答案(点此获取答案解析)

C

同类题2

阅读理解

Protect Children from Cyber-bullying

    When you think about bullying, you might think of a child being bullied by another in the schoolyard. As more young people have access to computers and cell phones, traditional bullying has gone digital, which has not yet gained awareness in Chinese parents.

    Cyber-bullying, first invented by Canadian educator Bill Belsey, is the use of the Internet and related technologies to harm other people, in an intentional, repeated, and unfriendly manner. It involves threatening text messages, the spread of online rumors on social networking sites, and intentionally keeping someone out of an online group. Cyber-bullying is at an all-time high in the US. According to a study from the US Department of Justice, more than 43% of teenagers report being victims(受害者)of cyber-bullying.

    Compared to face-to-face bullying, cyber-bullying is considered to have a worse emotional effect on the victims, and kids could feel more desperate and depressed. Severe, long-term or frequent cyber-bullying can leave victims at greater risk for anxiety, depression, and other disorders. Research says that cyber-bullying victims were almost twice as likely to have attempted suicide compared to youths who had not experienced it.

    In traditional schoolyard bullying, at least home is a safe place for the victims. But cyber-bullying is endless---it could happen anytime. Moreover, in the digital world, bullying is much easier, as a bully can pick on people with a much lower risk of being caught.

    Actually, cyber-bullying has become a worldwide issue. In the US, as several teens committed suicide because of cyber-bullying, some schools set rules to punish cyberbullies. Laws to punish cyber-bullying have been introduced in some states. In China, cyber-bullying is still considered by many parents and educators as a problem that involves physical contact. However, as cell phones and laptops are becoming common equipment for teenagers, social interactions have increasingly moved from personal contact to virtual contact. Cyber-bullying is spreading faster than expected.

    For schools and parents, safety rules should be set in the virtual world for kids, such as telling them not to let out anything to a stranger. Active steps should be taken to make the public aware of the seriousness of this problem, because it would be too late to take measures after tragedy strikes.