平达喜是常用的中和胃酸的药物,它的化学成分是铝和镁的碱式碳酸盐(含有结晶水),其

题型:问答题

问题:

平达喜是常用的中和胃酸的药物,它的化学成分是铝和镁的碱式碳酸盐(含有结晶水),其中氢元素的质量分数为0.040.取该碱式盐3.01g,加入2.0mol•L-1盐酸使其溶解,当逐滴加入盐酸42.5mL时,开始产生CO2,加入盐酸至45.0mL时正好反应完全.若在上述碱式盐溶于盐酸后的溶液中加入过量的氢氧化钠,过滤,沉淀物进行干燥后重1.74g.请计算该试样中:

(1)碳酸根的物质的量;

(2)镁离子的物质的量;

(3)氢氧根离子和铝离子的物质的量;

(4)写出碱式碳酸盐的化学式.

考点:物质的量的有关计算
题型:问答题

塑料门、窗框与墙体间缝隙应采用闭孔弹性材料填嵌饱满,表面应采用密封胶密封。密封胶应黏结牢固,表面应光滑、顺直、无裂纹,其检验方法正确的是( )。

A.尺量检查

B.观察检查

C.手扳检查

D.用弹簧秤检查

E.检查隐藏工程验收记录

题型:问答题

Mr. Smith liked his job. He liked his town, and he didn’t like the idea of moving somewhere else, but his wife   51  telling him that his pay was not enough to   52     the needs of the family. That was why he was thinking of taking a new job in Boston,  53  he had been offered a job in a factory, and the pay was far   54 .

Henry Manley, boss of Mr. Smith, was the   55  of a small company   56 computers. The company was in   57  trouble, because among other reasons, the Japanese were selling such things at very   58  prices. As a result, Manley had to   59    his own price and profits (利益) as well, otherwise he would not   60  any orders at all. Even so, orders were   61  not coming in fast enough,   62  there was no money for raises for his workers. Somehow, he had to   63  along and keep his   64  workers as well. He sighed (叹气) .    65  then the telephone rang.

His secretary told him that Mr. Smith wanted to   66  him as soon as possible. Manley   67  again. He could   68  what it was about. Mr. Smith was a very young engineer. The company had no   69  unless it could attract men like him. Manley rubbed his forehead: his   70  seemed endless.

小题1:.

A.considered

B.advised

C.began

D.kept小题2:.

A.meet

B.imagine

C.bring

D.tell小题3:.

A.there

B.where

C.here

D.somewhere小题4:.

A.lower

B.more

C.higher

D.less小题5:.

A.secretary

B.manager

C.customer

D.engineer小题6:.

A.making

B.to make

C.made

D.was making小题7:.

A.little

B.its

C.no

D.few小题8:.

A.tall

B.high

C.low

D.short小题9:.

A.raise

B.cut

C.keep

D.hold小题10:.

A.place

B.get

C.give

D.carry out小题11:.

A.already

B.obviously

C.still

D.undoubtedly小题12:.

A.because

B.even if

C.so that

D.even小题13:.

A.walk

B.struggle

C.come

D.give in小题14:.

A.best

B.strongest

C.youngest

D.kindest小题15:.

A.Even

B.Just

C.Suddenly

D.Immediately小题16:.

A.warn

B.leave

C.help

D.see小题17:.

A.waited

B.set back

C.sighed

D.telephoned小题18:.

A.think

B.know

C.expect

D.understand小题19:.

A.future

B.money

C.computers

D.people小题20:.

A.company

B.headache

C.problem

D.question

题型:问答题

(15分)

(1)(6分)下列说法正确的是________。(填入选项前的字母,有填错的不得分)

A.天然放射现象的发现,揭示了原子核是由质子和中子组成的

B.卢瑟福的α粒子散射实验揭示了原子核有复杂结构

C.玻尔的原子结构理论是在卢瑟福的核式结构学说基础上引进了量子理论

D.α射线,β射线,γ射线本质上都电磁波,且γ射线的波长最短

(2)(9分)质量为2kg的平板车B上表面水平,原来静止在光滑水平面上,平板车一端静止着一块质量为2kg的物体A,一颗质量为0.01kg的子弹以600m/s的速度水平瞬间射穿A后,速度变为100m/s,如果A B之间的动摩擦因数为0.05,求:

①A的最大速度;             

②若A不会滑离B,求B的最大速度。

题型:问答题

油脂能保持产品组织柔软,延缓(),延长点心的保存期。

A、淀粉糊化时间

B、淀粉老化时间

C、点心氧化时间

D、点心干化时间

题型:问答题

在班轮运输中承运人通常要求托运人送货至其指定的码头仓库或堆场交货,收货人在承运人指定的码头仓库或堆场提货。

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