问题 选择题

下列溶液中各微粒的浓度关系不正确的是

A.0.1 mol·L1 HCOOH溶液中:c(HCOO)+c(OH)=c(H)

B.1 L 0.l mol·L1CuSO4·(NH4)2SO4·6H2O的溶液中:

c(SO42)>c(NH4))>c(Cu2)>c(H)>c(OH)

C.0.1 mol·L1NaHCO3溶液中:

c(Na)+c(H)+c(H2CO3)=c(HCO3)+c(CO32)+c(OH)

D.等体积、等物质的量浓度的NaX和弱酸HX混合后的溶液中:c(Na)>c(HX)>c(X)>c(H)>c(OH-)

答案

CD

A符合电荷守恒,正确。B中铜离子和铵根离子均水解显酸性,所以B正确。C不正确,根据电荷守恒可知应该是c(Na)+c(H) =c(HCO3)+2c(CO32)+c(OH)。D中溶液的酸碱性是无法确定的,且也不符合电荷守恒,不正确。所以正确的答案是CD。

选择题
阅读理解

     Food is life; it gives us the nourishment (营养) we need to stay alive and be healthy.  __1__  

Brian Wansink, a professor at the University of Illinois, says we also eat certain foods because they

make us feel good, and remind us of happy memories. Wansink calls this kind of food comfort food.

For some people, ice cream is a comfort food. For others, a bowl of noodles soup makes them feel

good.  

     __2__   Professor Wansink believes that we connect food with important times, feelings, and people

in our lives. "When I was a child, my mother made a delicious soup; I loved it. __3__   And it helps me

feel better, " says one of Wansink’s coworkers.

     Do men and women choose different comfort foods? Wansink's research at the University of Illinois

says "yes". In his study, the favorite comfort food for both men and women was ice cream. After this,

men usually preferred hot, savory (香的) foods like soup or noodles.   __4__   Men and women like to

eat comfort foods when they are happy, but women eat these foods more when they are sad or worried.  

     __5__   About 40 percent of the comfort foods in Wansink's study were healthy main dishes or

soups and vegetables. It shows, says Wansink, that a comfort food can taste good and be good for you.  

A. Not all comfort food is junk food.

B. Where can we buy this sort of food?

C. Sweet foods are also their preference.

D. How does a food become a comfort food?

E. Usually, we eat because we are hungry or need energy.

F. Women like sweet things such as chocolate and cookies.

G. Now, I often have this kind of food when I am tired or worried.