利用硫酸渣(主要含Fe2O3、SiO2、Al2O3、MgO等杂质)制备氧化铁的工

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问题:

利用硫酸渣(主要含Fe2O3、SiO2、Al2O3、MgO等杂质)制备氧化铁的工艺流程如下:

(1)“酸浸”中硫酸要适当过量,目的是:①提高铁的浸出率,②            

(2)“还原”是将Fe3转化为Fe2,同时FeS2被氧化为SO42,该反应的离子方程式为

                                                             

(3)为测定“酸浸”步骤后溶液中Fe3的量以控制加入FeS2的量。实验步骤为:

准确量取一定体积的酸浸后的溶液于锥形瓶中,加入HCl、稍过量SnCl2,再加HgCl2除去过量的SnCl2,以二苯胺磺酸钠为指示剂,用K2Cr2O7标准溶液滴定,有关反应方程式如下:

2Fe3+Sn2+6Cl=2Fe2+SnCl62

Sn2+4Cl+2HgCl2=SnCl62+Hg2Cl2↓,

6Fe2+Cr2O72+14H=6Fe3+2Cr3+7H2O。

①若SnCl2不足量,则测定的Fe3           (填“偏高”、“偏低”、“不变”,下同)。

②若不加HgCl2,则测定的Fe3               

(4)①可选用             (填试剂)检验滤液中含有Fe3+。产生Fe3+的原因是

                                             (用离子反应方程式表示)。

②已知部分阳离子以氢氧化物形式沉淀时溶液的pH见下表:

沉淀物Fe(OH)3Al(OH)3Fe(OH)2Mg(OH)2Mn(OH)2
开始沉淀2.73.87.59.48.3
完全沉淀3.25.29.712.49.8
实验可选用的试剂有:稀HNO3、Ba(NO3)2溶液、酸性KMnO4溶液、NaOH溶液,要求制备过程中不产生有毒气体。请完成由“过滤”后的溶液模拟制备氧化铁的实验步骤:

a. 氧化:                              

b. 沉淀:                               

c. 分离,洗涤;             d. 烘干,研磨。

考点:氧化铁单质铁碱式碳酸铜氧化铜
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据有关媒体报道,近年来,湖南洞庭湖内江豚大量死亡已触目惊心,引起了社会广泛关注.请根据所学知识回答与江豚有关的问题.

(1)在生物分类学上,江豚与海豹同纲不同目,江豚与扬子鳄同门不同纲.请说出这两组生物之间谁的共同特征多______.

(2)江豚主要以小型鱼类为食.鱼类为了逃避江豚的追捕,常用其身体上的______来感知水流和方向.

(3)在“浮游植物→水蚤→小鱼→江豚”这条食物链中,有毒物质汞在______体内积累最多.

(4)江豚虽然外形象鱼并生活在水中,但是它进行繁殖和哺育后代的方式与人类相似,具有______的特征,因此它属于哺乳动物.

(5)请你向有关部门提出一条保护江豚的具体措施:______.

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2006年广东省价格变动情况

根据表格,以下正确的一项是()。

A.与上一年相比,肉禽及其制品的价格有所上浮

B.上表中,除了蛋类和衣着的价格下降外,其他产品价格均比上一年上浮

C.总体来说,各类居民消费价格比上一年有所上浮

D.衣着类的下降幅度最为明显

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I was a single parent of four small children, working at a low paid job. Money was always tight, but we had a (1) over our heads, food on the table, clothes on our backs, and if not a lot, always (2) . Not knowing we were poor, my kids just thought I was (3) . I’ve always been glad about that.

It was Christmas time, and although there wasn’t (4) for a lot of gifts, we planned to celebrate with a family party. But the big (5) for the kids was the fun of Christmas (6) .

They planned weeks ahead of time, asking (7) what they wanted for Christmas. Fortunately, I had saved MYM120 for (8) to share by all five of us.

The big (9) arrived. I gave each kid a twenty-dollar bill and (10) them to look for gifts of about four dollars each. Then everyone scattered. We had two hours to shop; then we would (11) back at the "Santa’s Workshop".

Driving home, everyone was in high Christmas spirits, (12) my younger daughter, Ginger, who was unusually (13) . She had only one small, flat bag with a few candies—fiftycent candies! I was so angry, but I didn’t say anything (14) we got home. I called her into my bedroom and closed the door, (15) to be angry again. This is what she told me.

"I was looking (16) thinking of what to buy, and I (17) to read the little cards on the ’Giving Trees’. One was for a little girl, four years old, and all she (18) for Christmas was a doll. So I took the card off the tree and (19) the doll for her. We have so much and she doesn’t have anything. "

I never felt so (20) as I did that day.

11()

A.draw 

B.stay 

C.move 

D.meet

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男性,48岁,有肝硬化病史8年,最近出现腹水而在家休息。4天前开始解黑便,今天淡漠少言,反应迟钝来就诊,怀疑有肝性脑病可能。

关于肝性脑病的诱发因素与下列哪项因素无关

A.上消化道出血
B.疼痛
C.摄入大量高蛋白饮食
D.大量放腹水
E.感染

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《中医药条例》规定,依法设立的社区卫生服务中心(站),乡镇卫生院等城乡基层卫生服务机构,应当能够提供()

A.基本医疗服务

B.群众保健服务

C.中医医疗服务

D.康复服务活动

E.推拿按摩服务

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