问题 选择题

在2L密闭容器中,发生3A(气)+B(气) ==2C(气)的反应,若最初加入A和B都是4mol,A的平均反应速率为0.12mol/(L·s),则10秒钟后容器中B的物质的量为(    )

A.2.8mol

B.1.6mol    

C.3.2mol

D.3.6mol

答案

答案:C

由于反应速率之比是相应的化学计量数之比,所以根据A的反应速率可知,B的反应速率是0.12mol/(L·s)÷3=0.04mol/(L·s)。所以B的物质的量变化是0.04mol/(L·s)×10s×2L=0.8mol,因此剩余B是4mol-0.8mol=3.2mol,答案选C。

阅读理解

Vivi Mac, an amazing artist from France, can use nearly any kind of food to create detailed celebrity portraits(名人肖像).Although she has yet to display her short-lived work of arts in a proper art gallery, Vivi Mac has already made a name for herself online.

We've seen some amazing food artists in the past, but none are quite like this one .Karen Eland is a master coffee painter, Elisabetta Rogai uses wine as her medium(媒介),Kelly McCollam uses food colouring(食用色素)to recreat classic paintings, but the self-taught Vivi Mac can take anything from chewing gum to milk and turn it into a fantastic portrait  When working with liquids, Mac uses a simple plastic straw and her hands to guide the unusual .mediums around a plastic plate which acts as a painting. Just how she manages to capture the finest facial features  is still a mistery  to me, and I've seen videos of her doing it many times,

Vivi Mac has never attended art school. She only used online resources like blogs and facebook to learn the basics of drawing and painting. She started out working with pens and paper, but soon realized drawing wasn't just creative enough for her. She got into speed  painting and body painting, posting videos of her works on You Tube, but it wasn't until she began experimenting with different kinds of foods that her art got serious coverage. Photos and videos of her eatable celebrity portraits, like Bruce Lee in milk  Ice Cube in crushed ice or Amy Winehouse in wine, became popular on the French inter-webs and changed Vivi Mac into an online celebrity.

小题1:What does the underlined word "display" in the first paragraph mean?

A.Exhibit.

B.Create.

C.Produce.

D.Store.小题2:What is the difference between Vivi Mac and other food artists?

A.She Uses wine as her medium.

B.She is famous for her food website.

C.She turns any kind of food into a portrait

D.She uses spices to recreate classic paintings.小题3:In which section of a website are we most likely to find the passage?

A.Food

B.Science

C.Art

D.Health

问答题 简答题