Scientific identification of the problem

The flame color reaction is a physical change. The essence is that the electrons get the energy, and the electron layer jumps in.

Identification of CuSO4 Na2CO3

Physics 1The color of the solution is not the same.

2.Flame color reaction.

3.Atomic spectrometer (invincible).

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Chemistry 1Add hydrochloric acid, nitric acid, sulfuric acid, cuso4 has no reaction, and Na2CO3 has bubbles.

na2co3+2hcl==2nacl+h2o+co22.In Fe Zn mg Al CuSO4, there was Cu precipitation on the metal surface, and Na2CO3 was not reacted.

fe+cuso4==feso4+cu

3.With the addition of litmus, cuso4 is neutral or weakly acidic, and Na2CO3 is alkaline (pH difference due to hydrolysis).

4.The addition of sodium hydroxide CuSO4 has a blue precipitate of Na2CO3 without phenomenon.

CuSO4+2NaOH ==Cu(OH)2+Na2SO4 to distinguish Ca(OH)2 and H2O

1.The pH is tested, the former is alkaline, and the latter is neutral.

2.Heating the Ca(OH)2 solution will become cloudy and H2O will not change.

3.Introduce an appropriate amount of CO2 and precipitate to produce Ca(OH)24Copper sulfate, sodium carbonate or ferric chloride are added, and Ca(OH)2 is formed by precipitation

Physically, the solution is one blue and one transparent.

Chemical, Na2CO3 plus litmus turns red.

CuSO4 plus Fe has Cu precipitation.

Na2CO3 heats up with bubbles.

CuSO4 plus NaOH is precipitated.

Ca(OH)2 plus CO2 is precipitated.

Ca(OH)2 plus Agno3 is precipitated.

Ca(OH)2 plus MgNO3 is precipitated.

Ca(OH)2 has a low boiling point.

Physics: Look at the color, the former is blue, the latter is colorless.

Chemistry. 1.It is added to a solution of hydrochloric acid, which releases gas.

2.When added to a sodium hydroxide solution, the former forms a blue precipitate.

3.A calcium hydroxide solution is added, which produces a white precipitate.

4.The flame color reacts, the former is green, the latter is yellow.

1.Check pH, the former is greater than 7, and the latter is equal to 7

2.A solution of copper sulfate is added, and the former generates a blue precipitate.

3.A sodium carbonate solution is added, and the former produces a white precipitate.

4.Magnesium sulfate solution is added, and the former produces a white precipitate.

Physics: Look at the colors, the former is blue, the latter is white.

Chemistry: CuSO4 does not react with HCl, Na2CO3+HCl==NaCl+H2O+CO2 (untrimmed).

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The introduction of calcium hydroxide carbon dioxide can produce calcium carbonate precipitation, and there is no phenomenon in water.

Calcium hydroxide is blue after being added to litmus reagent, and there is no phenomenon in water.

Calcium hydroxide turns red after adding phenolphthalein, and there is no phenomenon in water.

After calcium hydroxide is added to ammonium chloride, there is ammonia odor, and there is no phenomenon in water.

After calcium hydroxide is added to dilute hydrochloric acid, the solution is warmed up, and there is no phenomenon in water.

After calcium hydroxide is added to magnesium chloride, there is a flocculent precipitate that is insoluble in water, and there is no phenomenon in water.

I would like to ask the scope: secondary school? High school? University? Or is there no limit?

Forensic science is not the same as forensic science. The general public mistakenly believes that forensic science is a part of forensic science, so in the ** results of universities and the National Science Council, forensic science (forensic science) is classified in the field of forensic science (legal medicine), perhaps because in the 18th and early 19th centuries, most of the people engaged in forensic work worked in the forensic science departments of universities or research institutes. However, at the end of the 19th century and the beginning of the 20th century, forensic science underwent a great transformation, and many new knowledge and new sciences were born under the needs of forensic science, and forensic medicine became a part of forensic science.

In the early days, Taiwan's forensic science was mainly forensic and fingerprint, and the predecessors in the forensic field such as Ye Zhaoqu, Yang Risong, Fang Zhongmin, etc. were all advanced leaders in this field, and Zhao Moya was the most famous in fingerprinting. He was the first to study in the United States and obtain a master's degree from the John Jack College of Criminal Justice"Police University"Mr. Luo Yian, Vice President. It was not until 1983 that the branch of the South China Bank in Taipei City was robbed, Lin Yongquan was killed and his body was abandoned, and there was a carbine bullet at the scene.

At that time, he overcame all difficulties, found funds, and arranged for Lin Maoxiong and Weng Jinghui to come to the United States to meet me (Li Changyu)."Huayin robbery","Kill the police**"The firearms evidence was sent to my (Li Changyu) laboratory for examination. The two of them studied seriously during their time in the United States, and after opposing Taiwan, they became the pioneers of Taiwan's modern forensic work, which was also the time when Taiwan's forensic science began to sprout. Lu Yujun, the later director of the Criminal Police Commission, also strongly supported and managed to send Cheng Xiaogui and Xie Songshan to study in the United States.

They also worked very hard, working in the lab during the day, studying at the University of New Haven at night, and often going with me to the crime scene in the middle of the night to assist in the investigation.

Later, Yan Shixi took over from Taiwan"**Police Academy"In 1989, at the suggestion of Li Changyu, the Department of Forensic Science and the Department of Information Science were finally established, and these two new departments have cultivated many outstanding forensic personnel and computer and network information talents for Taiwan's police units. With the changes in the social environment, the demand for scientific case handling is getting louder and louder. Taiwan, 1996"Police University"Founded"Master's program at the Institute of Forensic Sciences", immediately after 2001"Doctoral program at the Institute of Forensic Sciences"of admissions.

This series of training programs for forensic professionals is also rare in the world. President Ngan has made many contributions to policing, and the establishment of these two departments is a visionary initiative to lay the foundation for the future trend of scientific case handling. At the same time, Wu Dongming took over"Legal Department"The Director of the Bureau of Investigation, who also took my suggestion to train forensic talents.

For example, now"Legal Department"Forensic doctor Xiao Kaiping of the Institute of Forensic Medicine, Liu Huang, Chen Li and others of the Sixth Division of the Investigation Bureau were all forensic personnel who had been specially trained at that time and made great contributions to Taiwan's forensic work.