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氧化镁在医药、建筑等行业应用广泛。硫酸镁还原热解制备高纯氧化镁是一种新的探索。以

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氧化镁在医药、建筑等行业应用广泛。硫酸镁还原热解制备高纯氧化镁是一种新的探索。以菱镁矿(主要成分为(MgCO3,舍少量FeCO3)为原料制备高纯氧化镁的实验流程如下:

(1)通入O2氧化时,发生反应的离子方程式为____________________。

(2)滤渣2的成分是_________(填化学式)

(3)流程图中“操作步骤”为                       、过滤等操作,得到MgSO4·7H2O晶体。对MgSO4·7H2O晶体直接加热       (填“能”或“不能”)得到无水MgSO4固体。

(4)长时间加热MgCO3悬浊液后生成Mg(OH)2,该反应的化学方程式为                                  

(5)已知酸碱指示剂百里酚蓝变色的pH范围如表所示:

pH< 8.08.0 ~ 9.6> 9.6
颜色黄色绿色蓝色
25℃时,向Mg(OH)2的饱和溶液中滴加2滴百里酚蓝指示剂,溶液所呈现的颜色为                  [25℃时,Mg(OH)2的溶度积Ksp=5.6×10-12)]。

(6)煅烧过程存在以下反应:

2MgSO4+C2MgO+2SO2↑+CO2↑; MgSO4+CMgO+SO2↑+CO↑;

MgSO4+3CMgO+S↑+3CO↑。

①若在实验室中煅烧硫酸镁,需要的仪器除酒精灯、三脚架以外,还需要        

A.蒸发皿      B.坩埚        C.泥三角        D.石棉网

②用下列实验装置检验煅烧产生的气体中含有SO2、CO2气体(加热装置略去,部分装置可以重复使用)。

正确的连接顺序是a→b→                       (按接口连接)。B中盛放的试剂是                ,确定存在二氧化碳气体的实验现象是                         

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In our life, we have rarely expressed our gratitude to the one who'd lived those years with us.In fact, we don't have to wait for anniversaries to thank the ones close to us —the ones so easily overlooked.If I have learned anything about giving thanks, it is this: give it now! While your feeling of appreciation is alive and sincere, act on it.Saying thanks is such an easy way to add to the world's happiness.

Saying thanks not only brightens someone else's world, it brightens yours.If you're feeling left out, unloved or unappreciated, try reaching out to others.It may be just the medicine you need.

Of course, there are times when you can't express gratitude immediately.In that case don't let embarrassment sink you into silence —speak up the first time you have the chance.

Once a young minister.Mark Brian, was sent to a remote parish of Kwakiuti Indians in British Columbia.The Indians, he had been told, did not have a word for thank you.But Brian soon found that these people had exceptional generosity.Instead of saying thanks, it is their custom to return every favor with a favor of their own, and every kindness with an equal or superior kindness.They do their thanks.

I wonder if we had no words in our vocabulary for thank you, would we do a better job of communicating our gratitude? Would we be more responsive, more sensitive, more caring?

Thankfulness sets in motion a chain reaction that transforms people all around us—including ourselves.For no one ever misunderstands the melody of a grateful heart.Its message is universal; its lyrics transcend (超越) all earthly barriers; its music touches the heavens.

53.In the first paragraph the writer mainly encourages us      .

A.never to overlook our close friends in daily life

B.to express our sincere thanks timely to those around us

C.to wait for a proper occasion to show our thanks

D.to increase the world's happiness by saying thanks

54.According to the writer,      could be the best way to prevent ourselves from being left out.

A.seeing a doctor to find the right medicine we need

B.expressing our thanks as much as we can

C.showing others actively we are interested in them

D.speaking up the moment we have the chance

55.Mark Brian's story is mentioned in the passage in order to show the fact that       .

A.the Indians didn't have any words for appreciation

B.the Indians were particularly generous to others

C.Mark Brian's set the Indians an example to show thanks

D.some people may express their thanks through different approaches

56.What message does the writer intend to communicate in the last paragraph?

A.Thanks is of great importance in developing harmonious relationship.

B.One grateful heart is surely to deserve another good one in return.

C.Thankfulness which goes beyond all barriers is universally understood.

D.Human beings would misunderstand each other without appreciation.

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