What is the phenomenon of sulfur dioxide being introduced into the purple litmus reagent?

Sulfur dioxide is introduced into the purple litmus solution: the solution turns red.

Reason: SO is passed into the purple litmus solution, which reacts with water to form H so (sulfurous acid), which is acidic, so the purple litmus solution will turn red.

Sulfur dioxide can fade the magenta solution because the color is restored after heating, because the bleaching principle of sulfur dioxide is that sulfur dioxide reacts with the bleached to form a colorless unstable compound, which destroys the p-quinone formula that plays a role in magenta, and when heated, the compound decomposes and returns to its original color, so the bleaching of sulfur dioxide is also called temporary bleaching.

Chlorine gas is passed into the purple litmus reagent, and the solution first turns red, and then the color fades, and does not change red after heating. The reason is that chlorine reacts with water to form HCl, HCLThe acidic solution meets the purple litmus reagent and turns red.

Hypochlorous acid has a bleaching effect, which fades the solution. HCl is volatile, after heating, HCl in the solution volatilizes in the form of gas, and the solution can no longer turn red.

SO2 is passed into the medium purple litmus reagent, and the solution first turns red, then fades, and then turns red after heating. The reason is that sulfur dioxide reacts with water to form sulfurous acid (reversible reaction), and the solution is acidic and turns red when it encounters purple litmus reagent. SO2 has a bleaching effect, which fades the solution.

When heated, the reaction shifts forward, and sulfurous acid reacts with O2 to form sulfuric acid, which is relatively stable in nature. The solution has turned red.

Is there such a statement?

The first reddening is because the sulfur dioxide dissolves in water to form an acidic substance, the purple litmus solution turns red, and then fades because the sulfur dioxide is saturated, and it has a bleaching effect, so too much sulfur dioxide bleaches the solution.

Chlorine gas has strong oxidizing properties, and when it is introduced into purple litmus, it will oxidize the purple litmus, causing it to be destroyed.

Sulfur dioxide is dissolved in purple litmus solution to form sulfurous acid, which makes purple litmus red, and after heating, sulfurous acid decomposes due to instability, and the solution returns to its original color.

SO2 + H2O = S2SO3 (reversible), the rest is difficult to write.

Hope satisfied.

Sulfur dioxide is introduced into the purple litmus solution: the solution turns red. SO2 is dissolved in water to form H2SO3, which is moderately strong acid and acidic, so the purple litmus solution turns red.

It should be noted that the reason why sulfur dioxide fading the red magenta solution is that SO2 is synthesized into H2SO3 (sulfurous acid) in water, which will have an addition reaction with some specific colored organic compounds to form unstable colorless organic compounds, which is caused by the instability of the product.

Sulfur dioxide physical properties.

Liquid sulfur dioxide is relatively stable and inactive. Gaseous sulfur dioxide is heated to 2000 without decomposition. It does not burn, and it does not form a ** mixture with air.

Inorganic compounds such as bromine, boron trichloride, carbon disulfide, phosphorus trichloride, phosphoryl chloride, iodine chloride, and various thionyl chlorides can be mixed with liquid sulfur dioxide in any ratio. The solubility of alkali metal halides in liquid sulphur dioxide decreases in the order of i->br >cl. Most metal oxides, sulfides, sulfates, etc. are insoluble in liquid sulfur dioxide.

Sulfur dioxide is introduced into the purple litmus solution: the solution turns red.

Reason: SO is passed into the purple litmus solution, which reacts with water to form H so (sulfurous acid), which is acidic, so the purple litmus solution will turn red.

Note: Sulfur dioxide can fade the magenta solution, because the color is restored after heating, because the bleaching principle of sulfur dioxide is that sulfur dioxide reacts with the bleached to form a colorless unstable compound, which destroys the p-quinone formula that plays a role in magenta, and when heated, the compound decomposes and returns to its original color, so the bleaching of sulfur dioxide is also called temporary bleaching.

However, there is no substance in the purple litmus solution that reacts with sulfur dioxide, so it will not fade.

Sulfur dioxide is introduced into the purple litmus solution, and the solution turns red. It should be noted that the reason why sulfur dioxide fading the red magenta solution is that SO2 is synthesized into H2SO3 sulfurous acid in water, which will undergo addition reaction with some specific colored organic compounds to form unstable colorless organic compounds, and the instability of the product leads to a reversible reaction.

Hazards of sulphur dioxideThe main harm of sulfur dioxide to the human body is the most clinically reported damage to the respiratory system, and the damage to the respiratory system mainly occurs in airway obstructive diseases, such as bronchitis, asthma, emphysema, etc., and even closely related to lung cancer.

Sulfur dioxide absorbs ultraviolet rays, which causes vitamin D deficiency in the human body, increasing the risk of colorectal cancer and breast cancer. The effect of sulphur dioxide on the cardiovascular system is mainly due to the increased incidence of ischemic heart disease.

After sulfur dioxide gas is introduced, it will react with the water in the test solution to form sulfurous acid, and the purple litmus test solution will be red when it encounters acid. As for the non-fading, because the sulfurous acid can be oxidized into sulfuric acid in the air, the solution is still an acid solution after placement, and the sulfur dioxide here reflects the nature of its acidic gas, and does not reflect bleaching, which is an irreversible process, so it does not fade.

Litmus (the main component is represented by HL) can be ionized in aqueous solution as follows: HL red H+L-blue.

In acidic solutions, red molecules are the main form of existence, and the solution appears red; In alkaline solutions, the ionization equilibrium shifts to the right, and blue ions are the main form of existence, and the solution appears blue; In a neutral solution, red molecules and blue acid ions exist at the same time, so the solution appears purple.

(1) Because of SO2

Similar to the chemical properties of CO2, carbon dioxide itself is not acidic, so it cannot discolor dried litmus; Water is a neutral liquid and cannot discolor dried litmus; The carbonic acid produced by the joint action of carbon dioxide and water is acidic, which can make the dried litmus change color; Therefore, neither sulfur dioxide nor water can change the color of dried litmus, but the action of sulfurous acid produced by the reaction of sulfur dioxide and water, so the experiment is designed as follows: Problem hypothesis.

Experimental operations and phenomena.

Conclusion. ①h2

o Cannot make purple litmus red.

Take a dried litmus and spray it with water to not change color.

The assumption is true. ②so2

It can make purple litmus turn red (or SO2

Purple litmus cannot be turned red).

Place a dried purple litmus into a bottle of SO2

gas, observe not changing color.

The assumption is not true (or the assumption.

Founded) h2

SO3 can turn purple litmus red.

Place the water-sprayed litmus into a bottle of SO2

gas, turn red. The assumption is true.

Therefore, the answer is: (1) The question is falsely designed to disturb the prudence.

Experimental operations and phenomena.

Conclusion. Take a dried litmus and spray it with water to not change color.

The assumption is true. ②so2

It can make purple litmus turn red (or SO2

You can't make Li Tong's purple litmus red, only respectful color).

The assumption is not true (or the assumption.

Set) Place the water-sprayed litmus into a bottle of SO2

gas, turn red.

2) a The closure of all factories is not in line with reality and therefore wrong;

b. Factory exhaust gas and automobile exhaust gas are discharged after reaching the standard, which can prevent and control air pollution, so it is correct;

c The use of clean energy can prevent and control air pollution, so it is correct;

So the answer is: b, c