问题 实验题

(11分) “酒是陈的香”,就是因为酒在储存过程中生成了有香味的乙酸乙酯,在实验室我们也可以用如图所示的装置制取乙酸乙酯。回答下列问题:

(1)写出制取乙酸乙酯的化学反应方程式:

                                  

(2)试管B中盛放的溶液是                ,其主要作用是                  

                                                                                                        

(3)装置中通蒸气的导管不能插入试管B的溶液中,目的是         

(4)若要把制得的乙酸乙酯分离出来,应采用的实验操作是       

(5)做此实验时,往往还向大试管A中加入几块碎瓷片,其目的是      

(6)用30g乙酸与46g乙醇反应,如果实际产量是理论产量的67%,则实际得到乙酸乙酯的质量是      

A.44g

B.29.5g

C.74.8g

D.88g

答案

(1)CH3COOH +C2H5OH CH3COOC2H5+H2O     (2分)

(2)饱和Na2CO3溶液;降低酯在水中的溶解度,除去酯中混有的醇和酸,利于分层。(1+3分)

(3)倒吸(1分) (4)分液(1分)  (5)防止暴沸(1分)(6)B(2分)

(1)实验室制取乙酸乙酯用乙酸和乙醇通过酯化反应生成,方程式CH3COOH +C2H5OH CH3COOC2H5+H2O。

(2)在反应过程中,乙醇和乙酸都乙挥发,所以要除去乙酸乙酯中的乙酸和乙醇,可以利用饱和碳酸钠溶液,其作用是降低酯在水中的溶解度,除去酯中混有的醇和酸,利于分层和闻到气味。

(3)由于乙酸和乙醇都是和水互溶的,所以为了防止倒吸,导管不能插入溶液中。

(4)乙酸乙酯不溶于水,分液即可。

(5)在反应过程中,需要加热,因此加入碎瓷片的目的是防止暴沸。

(6)根据方程式可知,46g乙醇如果完全酯化需要60g乙酸,因此乙酸是不足的,所以应该生成的乙酸乙酯是44g,所以实际生成的乙酸乙酯是44g×67%=29.48g,答案选B。

问答题 简答题
阅读理解

阅读理解

                                                             Thanks a Million, Dad

     I was born disabled.A difficult birth, feet first, my head stuck.By my first birthday, I couldn't stand

or walk.

     When I was three, the doctor told dad I had cerebral palsy (脑瘫).A loss of oxygen to my brain had

destroyed brain signals to the right side of my body.

     But no son of my dad' s was going to be disabled.Every morning before breakfast and every evening

before bed, my dad placed me on the bedroom floor to exercise my right leg.The muscles were shrunk

and twisted together.Back and forth up and down, my dad pushed and pulled the muscles into shape.

     But my dad' s exercise of passion didn't stop there.For my 13th birthday, he threw me a special

party.When everybody was gone, he brought me to open a large box, it was a-set of boxing gloves.

We put them on.My dad kept on beating me mercilessly.Each time I tried to get up, leather kissed

my nose, eyes and jaw.I "begged him to stop. He said he beat me to get me ready for the tough world.

    That same year, I was the only kid in my neighborhood that wasn't picked for Little League. Two weeks

later.Dad started the Shedd Park Minor League, and every kid played.Dad coached us and made me

a pitcher (棒球投手).

   The power of my dad' s love guaranteed I walked and more.In high school, I became a football star.

     In 1997, a brain surgeon in San Jose told me I didn't t have cerebral palsy after all.He explained how

and where the doctor' s forceps (镊子) at birth had damaged my brain.

     My dad never knew the whole truth since he passed away years ago.But all that counts is the bottom

line.After all his madness, on this Father' s Day, like every Father' s Day, I' m no longer disabled.

1.What caused the author' s disability?

A.A failed operation.

B.The doctor's forceps.

C.An accident in a game.

D.Shrunken and twisted muscles.

2.What do we learn from the passage?

A.The author has a talent for boxing.

B.The author achieved a lot thanks to his father' s love.

C.The author became a baseball star with the help of his father.

D.The author doesn't think his father should be so strict with him.

3.Paragraph 3 suggests that the author' s father____.

A.wouldn't give up hope easily

B.believed his son was a normal child

C.blamed the doctors for his son' s disability

D.couldn't accept the truth that his son was disabled

4.The author wrote the passage to ____.

A.remember his father

B.encourage disabled children

C.show the difficulty the disabled face

D.give advice to the parents of disabled children