更新1:
use these equipment only: Dilute hydrochloric acid,concentrated hydrochloric acid,nitric acid,silver nitrate solution,ammonia solution,lime water,distilled water,delivery tubes,test tubes,spatula,platinum wire,watch glasses
F.4 Chemistry問題
2012-10-01 3:35 am
Use simple chemical tests to identify NaCl,KNO3,CaCO3 and anhydrous copper(II) sulphate.
回答 (2)
2012-10-01 5:20 am
✔ 最佳答案
1. Mix silver nitrate solution+nitric acid with NaCl, white precipitate(ppt) will be formed.Others is colorless.
2. Add ammonia solution to copper(II) sulphate,
pale blue precipitate/ deep blue solution (when ammonia is in excess) will be formed.
Others no reaction.
For the remaining two, KNO3 can dissolve in water while CaCO3 cannot.
OR colorless gas bubbles(CO2) is formed when CaCO3 is mixed with any acid.
Others no reaction
2012-09-30 21:21:09 補充：
Do not use flame test because it is not considered as a chemical test!!!!
2012-10-02 11:23:20 補充：
I admit that my answer is not perfect.
Maybe you can tell us the correct answer.
2012-10-02 10:58 am
You'll not get any marks if you answer in this manner.
The biggest problem is that, you DON'T KNOW which one is which before tests.
You cannot "add silver nitrate & acid to NaCl", 'coz you just don't know which one is which.
2012-10-02 02:59:36 補充：
You only know there're 4 unnamed white solids, but you don't know which one is NaCl (before test).
This is some logics.
The biggest problem is that, you DON'T KNOW which one is which before tests.
You cannot "add silver nitrate & acid to NaCl", 'coz you just don't know which one is which.
2012-10-02 02:59:36 補充：
You only know there're 4 unnamed white solids, but you don't know which one is NaCl (before test).
This is some logics.
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