问题 填空题

某无色溶液X,由K、NH4+、Ba2、Al3、Fe3、CO32、SO42

中的若干种离子组成,取该溶液进行如下实验:

(1)白色沉淀甲是________。

(2)试写出实验过程中生成气体A、B的离子方程式

__________________________、_______________________________

(3)通过上述实验,可确定X溶液中一定存在的离子是

________,尚未确定是否存在的离子是________。

答案

(1)BaSO4

(2)CO32+2H=CO2↑+H2O NH4++OH NH3↑+H2O

(3)NH4+、CO32、SO42 K

溶液无色一定无Fe3;由①生成气体A可知溶液中一定含有CO32,A为CO2,有CO32一定无Ba2、Al3;由②生成气体B可知溶液中一定含有NH4+,B为NH3,生成白色沉淀甲可知溶液中一定含有SO42,甲为BaSO4,无法确定是否含有K

不定项选择
阅读理解

Over the past 20 years, AIDS and war have claimed the parents of 2.4 million Ugandan children.When Alexis Hefley first visited the country,, in 1993, she saw the children’s sorrow, but the former Texas banker also spotted "a world of possibility".She watched as they danced for tourists to earn money, and she had a thought: If people in America could see them perform, they’d support them too.                   

The children’s passion and talent inspired Hefley to work with the kids at an orphanage(孤儿院)in Kampala, the capital city of Uganda, to organize a traveling dance troupe(团).The goals: to give the problems in Uganda a human face, to raise awareness and to raise money.

The first tour touched down at six American cities in 1994.Today, the 22-member troupe, known as the Spirit of Uganda, travels across America every two years.The young performers bring their energy and joy to audiences across the U.S.and help support hundreds of Ugandan orphans back home.Among the young dancers, some earn scholarships to attend the U.S.colleges, and then return to their country to help rebuild it.

Photojournalist Douglas Menuez first photographed the troupe in 2006 -?a project that led to his new book, Transcendent Spirit, from which these images are drawn.At each performance, the dancers’ faces show pure joy, quite an achievement given the hardships they’ve faced."They look to the future, not the past," explains Menuez."They embrace beauty and good in the world." As one dancer puts it, "People think we have lost our parents.We’ve had so many problems.But then they see us perform.They see our smiles.And they learn that life goes on."

小题1:What are the first two paragraphs mainly about?     

A.How miserable Ugandan orphans’ life is.

B.How the dance troupe was set up.

C.How the young dancers earned money.

D.How the orphans lost their parents.|小题2:What do we learn about the Spirit of Uganda?            

A.It was started by a journalist.

B.It travels across the U.S.annually.

C.It consists of two dozen performers.

D.Its dancers have chances to study in the U.S.小题3:In the eyes of Menuez, the young performers are_____. 

A.beautiful

B.talented

C.optimistic

D.humorous小题4:What might be the most suitable title for the passage?      

A.Ugandan orphans turn tragedy into dance

B.Transcendent Spirit: A close look at Uganda

C.AIDS and war are claiming people’s lives

D.Lots of people are helping Ugandan orphans