问题 计算题

(10分)将体积为100 mL浓度为2.0 mol·L־1 的CuSO4溶液和体积为300 mL浓度为1.0 mol·L־1 的H2SO4溶液混合,假定混合后溶液体积为400 mL。计算:

(1)混合液中CuSO4的物质的量浓度是    ,H2SO4的物质的量浓度是    

(2)往混合液中加水稀释至Cu2+ 浓度为0.2 mol·L־1,则稀释后溶液的体积为            

(3)稀释后溶液中H+ 的物质的量浓度是    的物质的量浓度是     

答案

(1) 0.5 mol·L־1    0.75 mol·L־1   (2)1000mL   (3)0.6 mol·L־1   0.3 mol·L־1

题目分析:(1)n(CuSO4)=0.2mol       n(H2SO4)=0.3mol,混合后溶液的体积为400mL,所以c(CuSO4)=0.5mol/L  c(H2SO4)=0.75mol。

(2)根据c(稀)V(稀)=c(浓)V(浓)有0.2 mol·L־1×V=0.5mol/L×400mL,则V=1000mL。

(3)n(H+)=0.6mol  n(SO42-)=0.3mol,溶液体积为1L,则c(H+)=0.6mol/L,c(SO42-)=0.3mol/L。

点评:本题很基础,难度小,适合于训练学生的基础能力。

单项选择题

Although "naming rights" have proliferated in American higher education for the past several decades, the phenomenon has recently expanded to extraordinary lengths. Anything to get an extra dollar out of donors is fair game. I know colleges and universities sorely need to raise funds in these times of fiscal constraints, but things have gotten a bit out of hand.
Universities and colleges have long been named after donors-think of Harvard, Yale, Brown, and many others. John Harvard would hardly get a bench named after him today, given the modesty of his gift of books for the library back in the seventeenth century. Now it takes much more to get one’s name on a college. One institution, Rowan University of New Jersey, changed its name (from Glassboro State College) not long ago when a large donation was made. Buildings, too, have been affected. Traditionally, they were named after people such as distinguished scholars or visionary academic leaders; now they’re often named after big donors.
Why is all of this happening now The main motivation for the naming frenzy is, of course, to raise money. Donors love to see their names, or the names of their parents or other relatives, on buildings, schools, institutions, professorships, and the like. Increasingly, corporations and other businesses also seek to benefit from having their names on educational facilities. Today, no limits seem to exist on what can be named. If something does not have a name, it is up for grabs—a staircase, a pond, or a parking garage. Once all the major facilities have titles, lesser things go on the naming auction block. Colleges and universities, public and private, are all under increased pressure to raise money, and naming brings in cash.
It is unproductive. Separate branding weakens the focus and mission of an institution and perhaps even its broader reputation. It confuses the public, including potential students, and feeds the idea that the twenty-first-century university is simply a confederation of independent entrepreneurial domains.
The trends we see now in the United States, and perhaps tomorrow in other countries, will inevitably weaken the concept of the university as an institution that is devoted to the search for truth and the transmission of knowledge. All this naming distracts from the mission of an institution that has almost a millennium of history and cheapens its image. It is a sad symbol indeed of the commercialization and entrepreneurialism of the contemporary university.

The word "transmission" underlined in Paragraph 5 refers to ______.

A.spread

B.inculcation

C.cultivation

D.development

单项选择题 案例分析题