为了除去FeSO4溶液中少量的Fe2(SO4)3和CuSO4杂质,可选用的试剂是_爱下问搜题

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问题选择题

为了除去FeSO₄溶液中少量的Fe₂(SO₄)₃和CuSO₄杂质,可选用的试剂是（）

A．Fe

B．氨水

C．NaOH

D．氯水

答案

答案：A

氨水、NaOH 、氯水均可与FeSO₄反应并引入杂质离子，排除，答案为A

2Fe³^＋＋Fe=3Fe²^＋ Cu²^＋＋Fe=Fe²^＋＋Cu

填空题

阅读短文，用方框内所给单词的适当形式填空，使短文意思通顺、完整。（注意：①每个单词只能用一次。②其中有两个多余选项。）

everything, robot, spend, factory, fly, able, housework, answer, other, work, space, science

In one hundred years everyone will carry a small computer. The computer will give people the 1.______ to
all their questions. We will all have 2._______ at our home. So we'll be 3._______ to let robots do most of
the 4._______. While making a telephone call, we'll also be able to see the people on the 5._______ end at the
same time.
A lot of people will live and work under sea or in 6._______ because there will be big towns and 7._______
there. Robots will do most of the work, and people will just 8._______ two or three days a week. They'll be able
to 9._______ to the moon in a spaceship and 10._______ their holidays there.

判断题

第一次国际心理卫生会议与1937年在巴黎召开。