问题 选择题

下列说法中正确的是(  )

A.标准状况下,1mol水的体积是22.4L

B.只要是1mol气体,体积就是22.4L

C.0.3molN2 和0.7molO2,在标准状况下总体积为22.4L

D.1molNH3 在20℃、101kPa,体积约是22.4L

答案

A、水在标准状况下不是气体,标准状况下,1mol水的体积不是22.4L,故A错误;

B、只有在标准状况下1mol气体体积约为22.4L,故B错误;

C、0.3molN2 和0.7molO2,气体物质的量共为1mol,在标准状况下总体积为22.4L,故C正确;

D、1molNH3 在0℃、101kPa,体积约是22.4L,故D错误;

故选C.

选择题
单项选择题

Aspirin is one of the safest and most effective drugs invented by man. The most popular medicine in the world today, it is an effective pain reliever. Its bad effects are relatively mild. It is also cheap.For millions of people suffering from arthritis, it is the only thing that works. Aspirin, in short, is truly the 20th-century wonder drug. It is also the second largest suicide drug and is the leading cause of poisoning among children. It has side effects that, although relatively mild, are largely unrecognized among users.Although aspirin was first sold by a German company in 1899, it has been around much longer than that. Hippocrates, in ancient Greece, understood the medical value of tree barks and leaves which today are known to contain a chemical found in aspirin. During the 19th century, there was a great deal of experimentation in Europe with this chemical, and it led to the introduction of aspirin. By 1915, aspirin tablets were available in the United States.A small quantity of aspirin relieves pain and inflammation. It also reduces fever by affecting some of the body’’s reactions. Aspirin is very irritating to the stomach lining. The best way is to chew the tablets before swallowing them with water, but few people can stand the bitter taste. Some people suggest crushing the tablets in milk or orange juice.

According to this passage, ________may NOT be the right way to take aspirin.

A.chewing the tablets

B.swallowing the tablets

C.crushing them in milk

D.putting them in dishes