问题 选择题

百里酚酞是常用的滴定指示剂,pH小于9.4为无色,大于10.6时为蓝色,百里酚酞的结构式如右图,可由邻苯二甲酸酐等原料合成得到。有关说法不正确的是

A.百里酚酞中含有羟基、酯基及苯基等官能团

B.邻苯二甲酸酐分子中所有原子处于同一平面

C.1mol百里酚酞在溶液中最多可与4molNaOH反应

D.用已知浓度的烧碱滴定未知浓度的盐酸,用酚酞作指示剂比百里酚酞误差小

答案

答案:C

1mol百里酚酞在溶液中最多可与3molNaOH反应,酯基水解后得到的羟基并不能消耗氢氧化钠,C错误;酚酞变色范围在8.2到10,而百里酚酞是9.4到10.6,同样用氢氧化钠溶液滴定盐酸需要更多的氢氧化钠过量才能变色,故误差更大,D正确。

选择题
阅读理解
King Midas used to love gold. One day he met a fairy who allowed him to make a wish for something. The king replied at once , ‘‘I love gold . I want everything I touch to change into gold”. ‘‘Very well , tomorrow morning, everything you touch will turn into gold .”Saying this, the fairy disappeared.
The king waited excitedly till the next morning. To his joy ,everything he touched changed immediately into gold. ‘‘I’m the richest man in the world now.” He shouted.
Soon Midas became hungry. He sat down at his table. All the foods and drinks turned into gold in his hand . ‘‘I’m dying of hunger.” He cried.
Just then his daughter came running in . ‘‘Why are you so sad , dad ?” she asked, putting her arms around him. There and then she became a golden statue. The king loved his daughter very much .Seeing this ,he began to cry. He looked up and suddenly saw the fairy before him.  ‘‘Don’t you like the golden touch?” asked the fairy. ‘‘ Please take it away,” begged the king, ‘‘ give me back my daughter.”  ‘‘Well, you have learned your lesson. Go and wash in the river. Then the golden touch will be gone.” The king ran quickly to the nearby river.
小题1: The fairy allowed the king to make a wish because_____
A.she hoped to make the king the richest in the world.B.She loved gold too.
C.She wanted to teach the king a lesson.
D.She wanted to turn the king’s daughter into gold gold.
小题2: When the foods and drinks turned into gold the king was _____
A. excited  B. hungry  C. worried   D  happy
小题3: Which of the following might have happened afterwards?
A.The king died in the river.
B.The king’s daughter changed back from gold to a lovely girl.
C.All the things the king had touched changed back into real ones.
D.Both B and C
小题4:What do you think the story tries to tell us?
A.Gold makes people unhappy.
B.More gold , more happiness.
C.Gold is not the thing that makes life happy.
D.People feel happy if they have not gold.