问题 选择题

将由NaOH、BaCl2、Al2(SO)3三种固体组成的混合物溶于足量的水中,充分溶解,向混合溶液中滴加1mol·L-1的稀硫酸,加入稀硫酸的体积与生成沉淀的质量关系如图所示。下列有关判断不正确的是(    )

A.AB段发生反应的离子方程式为:Ba2++SO42-=BaSO4

B.E点对应横坐标稀硫酸的体积为70 ml

C.D点表示的沉淀的化学式为Al(OH)3、BaSO4

D.E点沉淀比A点沉淀质量大2.33g

答案

答案:A

题目分析:将由NaOH、BaCl2、Al2(SO)3完全溶解可能发生的反应有:Ba2++SO42-=BaSO4↓;4OH-+Al3+=AlO2-+2H2O. 向混合溶液中滴加1mol/L的稀硫酸,可能发生的反应有:A—B: Ba2++2OH-+2H++SO42-= BaSO4↓+2H2O ;B—C:H++OH-=H2O ;C—D:AlO2-+H+ +H2O=Al(OH)3↓;D—E:3H++Al(OH)3=Al3++ 3H2O.故选项A错误。根据从C---D与D—E的方程式可看出:使AlO2-转化为氢氧化铝沉淀消耗的H与使氢氧化铝沉淀溶解消耗的H的物质的量知比为:1:3,使AlO2-转化为氢氧化铝沉淀消耗的硫酸体积为10ml,所以溶解沉淀消耗硫酸体积为30ml..故到E 点一共消耗硫酸的体积是40ml+30ml=70ml.故选项B正确。根据上述反应过程中方程式的分析可得出D点表示的沉淀的化学式为Al(OH)3、BaSO4。选项C正确。A点是部分SO42-反应产生的沉淀值,E点是所有SO42-反应产生的沉淀值。根据A—B:Ba2++2OH-+2H++SO42-= BaSO4↓+2H2O的关系可知:n(BaSO4)= n(H2SO4)= 0.01L×1mol/L=0.01mol.故E点沉淀比A点沉淀质量大2.33g。正确。2、Al2(SO)3三种固体组成的混合物溶于足量的水中与硫酸反应的情况。

阅读理解

阅读理解。

     His songs are a bit sad, but his boy-like smile can quickly warm you up! And people love A-do for both

reasons.

     He has been singing for only two years, but he's already a famous star in Asia's pop world. The Singaporean

singer has already made three albums. Together they have sold more than five million copies across Asia.

     China's Music Radio named him "the Asian King of Pop". A-do said he didn't expect the award (奖)."It's

great for me. It makes me want to work even harder."

     His new album "Hello" came out in December. He sings with the same rough (粗糙的) voice, and he puts

in some rock music. In the "Hello" music video, Vicky Zhao (赵薇) is with A-do outside on a cold day in

Northern China.

     A-do used to be a house builder. Every day after work, he would sing by himself. Other workers heard

him and told him he should be in a contest.

     A-do hasn't changed much. He still gets nervous in front of cameras. Peng Yiting, a junior at a middle

school, says, "He's real and doesn't show off (炫耀). He's an everyday hero and shows anyone can do well

if they work hard."

1-2. 判断正(T)误(F)。 3. 译为汉语。 4 .补单词。 5. 选择。

(     )1. A-do's albums can warm you up.

(     )2. A-do has been singing for only two years.

3. China's Music Radio named him "the Asian King of Pop".

    ________________________________________________________________

4. Other workers heard him _____ and told him he should be in a contest.

5. What was A-do before he became a famous singer?

A. A builder.

B. A businessman.

C. A teacher.

单项选择题