a mixture contains copper powder and zinc powder.In order to remove the zinc powder , the mixture is heated with an acid and filtered.Which of the following acids should be used?
A. dilute nitric acid
B.concentrated nitric acid
C dilute sulphuric acid
D. concentrated sulphuric
Answer:C
Would you please tell me why the answer is C instead of D?
1993 chem q12
2010-03-03 2:21 am
回答 (1)
2010-03-03 2:44 am
✔ 最佳答案
The only difference between options C and D are the concentration of the acid.For C, it is diluted sulphuric acid, for D, it is concentrated sulphuric acid.
For concentrated sulphuric acid, it is a very strong oxidizing agent that it can oxidize copper and zinc. So, adding it to the mixture and heating it will remove both of the powders.
For diluted sulphuric acid, it can only oxidize zinc, not for copper. So it serves the purpose.
參考: Physics king
收錄日期: 2021-04-19 21:31:54
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20100302000051KK01049