问题 实验题

实验室用密度为1.18 g/mL、质量分数为36.5%的浓盐酸配制250 mL 0.1 mol/L的盐酸溶液,填空并请回答下列问题:

(1)配制250 mL0.1 mol/L的盐酸溶液

(2)配制时,其正确的操作顺序是(用字母表示,每个字母只能用一次)________________。

A.用30 mL水洗涤烧杯和玻璃棒2~3次,洗涤液均注入容量瓶,振荡

B.用量筒准确量取所需的浓盐酸的体积,沿玻璃棒倒入烧杯中,再加入少量水(约30 mL),用玻璃棒慢慢搅动,使其混合均匀

C.将已冷却的盐酸沿玻璃棒注入250 mL的容量瓶中

D.将容量瓶盖紧,摇匀

E.改用胶头滴管加水,使溶液凹面最低处恰好与刻度线相平

F.继续往容量瓶内小心加水,直到液面接近刻度线1- 2 cm处

(3)操作A中,将洗涤液都移入容量瓶,其目的是 ___________________ 。溶液注入容量瓶前需恢复到室温,这是因为_____________________________。

(4)若出现如下情况,对所配溶液浓度将有何影响?没有进行A操作________________;加蒸馏水时不慎超过了刻度线________________;定容时俯视______________ ;容量瓶内壁附有水珠而未进行干燥处理_____________ ;定容后摇匀液面低于刻度线______________ 。

答案

(1)

(2)B、C、A、F、E、D

(3)保证溶质全部转入容量瓶;容量瓶盛放热溶液时,体积不准

(4)偏低;偏低;偏高;无影响;无影响

填空题
阅读下列短文,根据短文内容填写表格,每空限填一词。

In today’s society, everyone is busy and running at a fast pace(步调) every day. We feel our time is valuable and needs to be used well. We need cheap meal ideas that can help us save time and money and still provide a healthy and nutritious (有营养的) dinner for us and our family.
The fast food makers know we have little time and that the idea of cooking dinner after a long day at work is not something we look forward to. So the fast food makers offer us cheap food that requires no cooking, no cleaning, and only 25 minutes to pick up.
But eating so much fast food will cause body fatness and fast food is not nutritious, so it’s not the healthiest choice to consider. There are some very cheap meal ideas that take almost no time to prepare and will make coming home for a good meal more enjoyable.
The first cheap meal idea is one dish which includes meat, vegetables and rice. This is not only a cheap meal idea, but also it is fast because it can be made in only 20 minutes.
You can quickly make some pancakes and scrambled eggs for the family in about 30 minutes. If you think it is strange to eat breakfast food for dinner, consider how the same foods give you what you need to go through a whole day.
Another cheap meal idea to try is a “macaroni and cheese with meat” dish, which only takes around 20 minutes to cook.
If you are interested in these cheap meal ideas, you’re welcome to visit our website for details. When you fix one of these or other cheap meal ideas at home, you are taking time out of your busy day to treat yourself and your family in a special way.
Facts
·(1)        life and valuable time
·Being in need of cheap and (2)        meals
(3)        of fast food
·No cooking
·No (4)        
·No wasting time
Disadvantages of fast food
·Making people get (5)        
·Having no nutrition
Three(6)        of cooking
·A (7)       with meat, vegetables and (8)        
Taking only 20 minutes
·Pancakes and scrambled eggs
Taking around (9)        minutes
·Macaroni and (10)          with meat
Taking about 20 minutes
 
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