问题 选择题

有关CaCO3的溶解平衡的说法中,不正确的是

A.CaCO3沉淀析出和沉淀溶解不断进行,但速率相等

B.CaCO3难溶于水,其饱和溶液几乎不导电,属于弱电解质溶液

C.升高温度,CaCO3沉淀的溶解度增大

D.向CaCO3沉淀中加入纯碱固体,CaCO3的溶解量降低

答案

答案:B

题目分析:A、达到平衡V沉淀溶解=V沉淀析出,正确;B、CaCO3难溶于水,但溶解的完全电离出离子,属于强电解质溶液,错误;C、一般的温度越高,溶解度越大,正确;D、纯碱电离出CO32-抑制CaCO3沉淀溶解,CaCO3的溶解量降低,正确。

阅读理解

阅读理解。

     Another year is coming! Time to forget the past, have a new start and party!

     People started celebrating the New Year about 4,000 years ago in Egypt. But New Year's Day

wasn't on January 1 until 46 BC (公元前)!

     During that year, Julius Caesar, the leader of the Roman Empire, made a new calendar. It made

January1 become New Year's Day.

     Today, people celebrate the day in many different ways.

     In the US, people have parties on December 31, New Year's Eve. The biggest party is in Times

Square, New York.

     There, at 11:59pm, a ball drops slowly down one of the buildings. It hits the ground at 12am, lighting

a sign reading "Happy New Year". It also sets off fireworks.

     Denmark has the strangest celebrations. There, on New Year's Eve, people throw plates at their

friends' homes as a sign of friendship!

     The Spanish also celebrate the New Year strangely. At 12am everybody eats 12 grapes! Why?

Because they think the grapes will bring them good luck.

     Why don't you try eating some this New Year's Eve?

1. People started celebrating the New Year in _________.

A. Rome      

B. Denmark      

C. the US    

D. Egypt

2. People celebrate the New Year _________.

A. for thousands of years

B. in the same way

C. only in Rome

D. for Julius Caesar

3. People eat ________ to celebrate the New Year in Spain.

A. dumpling    

B. noodles    

C. grapes    

D. cakes

4. In ________, People throw plates at their friends' homes on New Year's Eve.

A. Spain    

B. Denmark    

C. Rome    

D. Egypt

5. Which one is NOT right about the passage?

A. In the US, people have parties on New Year's Eve.

B. New Year is the time to forget the past.

C. In Denmark people throw plates to bring them good luck.

D. People celebrate the New Year in different ways.

名词解释