问题 计算题

实验室需要0.1 mol /L氢氧化钠溶液100 mL,现有2 mol /L氢氧化钠溶液。

(1)计算所需溶质氢氧化钠的质量是多少?

(2)计算所需2 mol /L氢氧化钠溶液的体积;

答案

阅读理解

D

  As the country's economy continues to steam ahead,once popular forms of entertainment,such as Karaoke(卡拉OK),card games and even boxing bars,appear to be losting their attractiveness.Stressed out white - collar wokers are camping out on rooftops,smashing(砸)up restaurants,pretending to be children and even visiting cemeteries in a effort to ease the pressure of modern life.

  Consider the members of Shanghai's Cat Rain club.By day,this group of young women work executive (决策管理的) jobs,but by night they climb buildings so they can spend the night on the roof."You feel relaxed when you're sitting on the roof,looking up to the sky and chatting with friends," said Gong Ying,25.

  The stress of work is not just limited to people in Shanghai.A recently opened restaurant in Beijing encourages customers(顾客) to smash plates --- as long as they are willing to pay to replace them.Some workers even wish to return to their childhoods.Recently,hundreds of people took part in a festival in which adults pretended to be children.It was an adultsonly event,and participants could read comics and eat sweets all day.

  Scenic places such as parks and rivers can also help people relax and put things in perspective.But a cemetery?

  Cemetery companies in Shanghai organized visits to local graveyards for stressed - out workers in March.The participants were taken to quiet spots in the cemetery where they could think about life and their futures."Pressure may bring us unhappiness,but it doesn't mean we can't find ways out,"says Chen Bin,a rooftop camping fan with still some other interests."Life should be imaginative."

  68.Peopel are going to those new activities mainly for ______.

   A.recreation   B.new ideas   C.physical refreshment   D.psychological relaxation

  69.The underlined phrase "put things in perspective"in the 4th paragraph possibly means______.

   A.have a good rest          B.get over negative feelings

   C.take physical exercise      D.judge things correctly

  70.When Chen Bin says:"Life should be imaginative",she means______.

   A.life should be lived in imaginations

   B.the dead can be alive in our imagination

   C.people should create new ways of life

   D.we should view life positively

填空题

(14分)草酸亚铁可用于合成锂电池的正极材料硅酸亚铁锂(Li2FeSiO4)等,其制备过程主要包括:

a.将硫酸亚铁铵(NH4)2Fe(SO4)2·6H2O晶体溶于适量蒸馏水,加入适量稀硫酸酸化。

b.将上述溶液煮沸,逐滴加入H2C2O4溶液,直至沉淀完全。

c.静置、倾去上层清液、过滤、洗涤、50℃以下烘干。试回答下列问题:

(1)配制(NH4)2Fe(SO4)2·6H2O溶液时,需加入少量稀硫酸,目的是          

(2)将制得的产品(FeC2O4·2H2O)在氩气气氛中进行热重分析,结果如图(TG%表示残留固体质量占原样品总质量的百分数)。

①则A-B发生反应的化学方程式为:                                 

②精确研究表明,B­-C实际是分两步进行的,每步释放一种气体,其中第一步释放的气体相对分子质量较第二步的小,试写出B-C两步反应的方程式:                     、

                                      

(3)Li2CO3、FeC2O4·2H2O和SiO2粉末均匀混合,在800℃. 的氩气中烧结6小时,即可制成硅酸亚铁锂。①合成硅酸亚铁锂的化学方程式为:                      

②该锂电池放电时的总反应式为LiFeSiO4+Li=Li2FeSiO4,写出相应的电极反应式:

正极                、负极