问题 选择题

用括号内物质一次性鉴别下列各种物质不能达到目的是(  )

A.HCl、Na2CO3、NH4Cl三种溶液(石灰水)

B.CuO、Fe、C三种固体(稀硫酸)

C.HCl、NaOH、Na2CO3 三种溶液(酚酞试液)

D.BaSO4、NH4NO3、NaCl三种固体(水)

答案

A、石灰水与盐酸反应生成氯化钙和水,无现象,碳酸钠与氢氧化钙反应生成碳酸钙沉淀和氢氧化钠,氯化铵与氢氧化钙反应生成氯化钙,氨气和水,所以分别取三支试管,分别加入石灰水,有白色沉淀生成的是碳酸钠,有刺激性气味气体生成的是氯化铵,没有现象的是盐酸,故A能达到目的;

B、氧化铜与硫酸反应生成硫酸铜和水,硫酸铜溶液是蓝色,铁与硫酸反应生成硫酸亚铁和氢气,硫酸亚铁溶液是浅绿色,碳与硫酸不反应,所以分别取三支试管,分别加入稀硫酸,黑色固体溶解溶液变为蓝色,说明是氧化铜;有气体产生,溶液变为浅绿色的是铁;不反应的是碳,故B能达到目的;

C、碳酸钠显碱性,与氢氧化钠都能使酚酞试液变红色,所以不能鉴别,故C不能达到目的;

D、BaSO4不溶于水、NH4NO3溶于水使溶液温度降低、NaCl溶于水溶液温度不变,故D能达到目的.

故选C.

选择题
阅读理解

Long long ago, there was a man who was good at shooting arrows.He asked the king to declare him as the greatest archer(射手) of the country.The king was about to do so when an old servant of the king said,“Wait,sir.I know an old man who lives in the forest.He is a much greater archer.Let this young man go to him and learn from him for at least three years.”

The man could not believe what the servant said,but he went and found the old man and he was! For three years he learned from him.Then one day,when he thought he had learned everything,the thought arose in him:“If I kill this old man,then I will be the greatest archer.”

The old man had gone to cut wood and he was coming back carrying wood on his shoulder.The young man hid behind a tree,waiting to kill him.He shot an arrow.The old man took a small piece of wood and threw it.It struck the arrow and the arrow turned back and wounded the young man very deeply.The old man came,took out the arrow and said。“I knew that some day or other you were going to do this.That’s why I have not taught you this secret.There is no need to kill me.My Master is still alive,and I’m  nothing before him.You must be  with him for at least thirty years.And he is very old,so go fast! Find the old man!”

小题1:The young archer wanted to kill the old man because_______.

A.he could then become the greatest archer

B.he had nothing more to learn from him

C.the old man refused to teach him everything

D.the king’s old servant ordered him to do SO小题2:What do you think would most probably happen next?

A.The young archer died from the wound soon after.

B.The king declared the young man the greatest archer.

C.The young archer found the old man’s master and killed him.

D.The young archer set off to look for the old man’s master.小题3:What lesson can you learn from the story?

A.Always use a piece of wood to protect yourself from an arrow.

B.You must never try to become better than your teacher.

C.The older a man is,the better archer he usually becomes.

D.There’s always someone better than you in this world.