Junior high school chemical ion test questions, junior high school chemistry common ion testing

First, the substance is dissolved in water or a solvent of any kind.

1.Chloride ion electrochemical method to produce chlorine gas, chlorine gas generation OK2Sulfate ions are added to barium hydroxide as if barium sulfate is a precipitate.

3.Ditto, add calcium hydroxide as if calcium carbonate is a precipitate.

4.Find a way to make ammonia, if there is OK

Originally, I thought -- seeing that the answers of the following people are so complete, and they are similar to mine, hehe, I won't fight with you.

Ion testing.

Hydrogen ions: add purple litmus test solution dropwise and add zinc grains.

Hydroxide ion: phenolphthalein test solution copper sulfate solution.

Carbonate ions: dilute hydrochloric acid and clarified lime water.

Chloride ions: silver nitrate solution and dilute nitric acid, if a white precipitate is produced, it is chloride ion sulfate ion: barium nitrate solution and dilute nitric acid First add dilute hydrochloric acid dropwise and then drop barium ammonium chloride ions:

Sodium hydroxide solution and heat, put the moistened red litmus test paper on the mouth of the test tube copper ions: add sodium hydroxide solution dropwise, if a blue precipitate is a copper ion iron ion: add sodium hydroxide solution dropwise, if a reddish-brown precipitate is iron ions.

Like acids and alkalis, phenolphthalein and Shi Lei test solution are generally used, phenolphthalein does not change color when it meets acid, it turns red when it is alkaline, it turns red when it is acid, it turns blue when it is alkaline, like Ca ions and Ba ions, if it is added like carbonic acid solution, it will produce white precipitate, if it is added HCL, if it is dissolved is Ca ion, it is Ba ion, and if it is K+ or Na+ ion and other metal ions, it can be tested with flame color reaction, probably so much! Please forgive me for the shortcomings and mistakes!

Junior high school chemical substance testing.

1) Ion detection.

1. H+: Add purple litmus test solution dropwise and add zinc grains.

2. OH-: phenolphthalein test solution copper sulfate solution.

3. Carbonate ions: dilute hydrochloric acid and clarified lime water.

4. Chloride ions: silver nitrate solution and dilute nitric acid, if white precipitate is produced, it is chloride ions 5. Sulfate ions: barium nitrate solution and dilute nitric acid First add dilute hydrochloric acid dropwise and then drop into barium chloride 6, ammonium ions:

Sodium hydroxide solution and heat, put the moist red litmus test paper on the mouth of the test tube 7, copper ions: add sodium hydroxide solution dropwise, if the blue precipitate is copper ion 8, iron ions: add sodium hydroxide solution dropwise, if the reddish-brown precipitate is iron ion (2), gas test.

1. Oxygen: Put the wooden strip with sparks into the bottle, if the wooden strip is re-ignited, it is oxygen 2. Hydrogen: ignite the gas at the glass tip, cover a dry cold small beaker, observe whether there are water droplets on the wall of the cup, pour clear lime water into the beaker, if it is not turbid, it is hydrogen

3. Carbon dioxide: pass into the clear lime water, if it becomes turbid, it is carbon dioxide 4. Ammonia: moist purple-red litmus test paper, if the test paper turns blue, it is ammonia 5. Water vapor: through anhydrous copper sulfate, if the white solid turns blue, it contains water vapor

Hydroxide test, first of all, from the acidity and alkalinity consideration, a solution is alkaline must have hydroxide ions, then the test method is to add some phenolphthalein test solution, if it turns red, it is alkaline, then contains hydroxide ions.

Other ions are also solved in the same way from his characteristics, and then hydrogen ions, then you first have to consider what characteristics it has, remember, it is the characteristics, if you want hydrogen ions can be oxidized into hydrogen, then this is not its characteristics, there are too many gases, this does not explain the problem, and you also prove that this gas can ignite with oxygen, generate water and do not produce other substances, which is too troublesome. The characteristic of hydrogen ions is that they are acidic, that is, all acidic solutions must have hydrogen ions. Knowing this feature, then it can be solved.

Take an appropriate amount of solution and drop it into the purple litmus test solution, if it turns red, it contains hydrogen ions, if it does not change or turns blue, there are no hydrogen ions (there must be hydroxide ions when it turns blue).

You can also look at the color and other aspects, for example, if you are asking about junior high school, then if I remember correctly, junior high school has such a few specific colored solutions, that is, the characteristics of some ions, for example, the solution is pale yellow, then there are iron ions, and the solution is light green, then there are ferrous ions; The blue color has copper ions.

Methods such as precipitation are generally not used unless it is expressly stated that there is a certain range within which precipitation is a characteristic. Or this precipitate is different from other precipitates and has properties, such as anhydrous copper sulfate (white precipitate) turns blue when exposed to water.

Ion testing.

1. Hydrogen ions: add purple litmus test solution dropwise and add zinc grains.

2. Hydroxide ion: phenolphthalein test solution, copper sulfate solution.

3. Carbonate ions: dilute hydrochloric acid and clarified lime water.

4. Chloride ions: silver nitrate solution and dilute nitric acid, if white precipitate is produced, it is chloride ions 5. Sulfate ions: barium nitrate solution and dilute nitric acid First add dilute hydrochloric acid dropwise and then drop into barium chloride 6, ammonium ions:

Sodium hydroxide solution and heat, put the moist red litmus test paper on the mouth of the test tube 7, copper ions: add sodium hydroxide solution dropwise, if it produces blue precipitate, it is copper ion 8, iron ions: add sodium hydroxide solution dropwise, if it produces reddish-brown precipitate, it is iron ions, then you look at this.

Common metal ions can be identified by color detection reaction, that is, according to the different colors to verify, non-metal ions can be identified by precipitation reaction, because there is no specific example I can only answer in general, if there is a question to continue to ask, I try my best.

silver nitrate for chloride ions; Ammonium ions are alkalin, which will produce ammonium gas; acids for carbonate ions; Barium chloride and dilute hydrochloric acid for sulfate ions; ...You better add me to the button, there are many, many days of my space, and I can't finish typing now. I'm done with my answer, welcome to it.

A silver ion touching the carbonate should also be precipitated.

b barium meets carbonate is also a precipitate.

The generation of copper sulfate by CCU ions and hydroxide ions is a blue precipitate d sodium sulfite and sulfuric acid reaction with SO2

It is also a colorless gas.

So C should be chosen

c1.False, it may be CO32-, and the dropwise addition of silver nitrate solution will also produce a white precipitate2False, it may be CO32- or SO32-, and the dropwise addition of barium chloride solution will also produce a white precipitate3Correct, the base is only copper hydroxide blue.

4.Error, probably so32-, so2 is also colorless.

The first question: hydrochloric acid can also be used, there is gas to produce sodium carbonate, and there is no phenomenon of sodium chloride. This is simpler, this is actually the test of carbonate ions and chloride ions, because cations are sodium ions, so by testing anions can distinguish substances.

However, if only silver nitrate is used, it cannot be identified, because sodium chloride and sodium carbonate can react with silver nitrate to form a white precipitate, so with silver nitrate, we also need to add acid to the precipitate to see if the precipitate capacity is dissolved, the insoluble is silver chloride, and the dissolved is silver carbonate.

The second question: the general test of chloride ions is silver nitrate and hydrochloric acid, in junior high school we have two insoluble salts in acid, silver chloride and barium sulfate, but can and silver ions, barium ions to produce precipitation and carbonate ions, that is, barium carbonate and silver carbonate, such as the identification of sodium carbonate and sodium sulfate, if we choose to use barium nitrate identification, then both solutions can produce white precipitate (barium carbonate and barium sulfate) with barium nitrate, so it can not be identified, at this time, we add nitric acid to the precipitation respectively, It is barium carbonate that produces gas (which can also be said to be precipitated and dissolved), that is, the original solution is sodium carbonate, and what is insoluble is barium sulfate, that is, the original solution is sodium sulfate.

I hope it can help you, so if you don't understand, you can continue to ask.

When Cl+ is present in this solution.