Chemistry Why are these three sentences wrong? Please explain a sentence in chemistry

A phenol is toxic and corrosive, and because of this its dilute solution can be used as a disinfectant and antiseptic, killing bacteria.

b White phosphorus has a very low ignition point, which is very easy to spontaneously combust, and it is not safe to make matches at all.

d When vinegar is descaled, it is the acid-base neutralization reaction between acetic acid and carbonate precipitation in the kettle, not the hydrolysis reaction.

A lot of things seem to be poisonous, but as long as they don't get absorbed, it's fine.

b How is it possible that the ignition point of white phosphorus is only about 40!

d. The concept and essence of salt hydrolysis.

1) Concept The reaction in which ions ionized by salt in solution combine with H or OH ionized by water to form weak electrolytes is called hydrolysis of salts.

2) Solid The weak ions in the salt combine with the H or OH ionized by the water to form a weak electrolyte, which breaks the ionization balance of the water, so that the solution is acidic or alkaline.

It's electrolysis.

A, can it be disinfected if it is toxic? It is even more unlikely to be used as a preservative.

b, red phosphorus is non-toxic, white phosphorus is toxic.

C, not a hydrolysis reaction, is a reaction of H ions with carbonate ions.

a, phenol is toxic and can be used for disinfection, as the saying goes, poison fights poison. The soaps we use every day contain (a small amount is beneficial and harmless).

b, white phosphorus ignition point is very low, commonly known as ghost fire, easy to natural, toxic, we use red phosphorus to make matches.

d, the scale is CaCO3, which can only be said to be a metathesis reaction, which has nothing to do with hydrolysis, and water does not participate in the reaction.

a.It doesn't have to be toxic.

b.White phosphorus ignition point is low.

d.It is the acidic substance that reacts with the salt.

, It is wrong that the ignition point of white phosphorus in b is high, because white phosphorus is stored in water, so the ignition point of white phosphorus is very low Such a good point to remember Oh, I only know this

Almost all chemical reactions have a certain degree of reversibility, so that the reaction can completely increase the yield and improve the economic benefits. Applying Le Chatletle's principle, it is possible to find a way to move the reaction in the direction of the positive reaction as much as possible.

"Blast furnace carburization" may be "blast furnace heightening". There is such a story in the history of industry: industrial countries use blast furnaces to make iron, and the reaction is the reaction of iron oxide and carbon monoxide, and it is not known that the reaction is reversible at that time, so whenever it is found that there is still iron oxide that has not been reacted after smelting a furnace, it is considered that the blast furnace is not high enough, and the contact time between the two reactants is short, so the price of the blast furnace.

Later, it was Le Chatre who proposed Le Chatlet's principle and solved this problem.

Blast furnace carburization means that the results are different (CO CO2) depending on the full reaction time conditions, such as the reaction of nitrogen and ammonia.

(1) No, the neutral pH value is different at different temperatures, and the pH<7 solution at 25 degrees Celsius is acidic. Pay attention to the temperature limit when doing the questions, it is easy to make mistakes.

2) Because acetic acid is a weak acid, it is not completely ionized. Dilution with water will promote ionization, so when the original pH = 3 (i.e. C(H+) = 10-3).

After diluting 100 times with water, the concentration of hydrogen ions is greater than 10 -5, that is, the pH<5(3)NaOH solution is mainly OH-, so the calculation should be based on OH-, C(OH-)=, and then use the -14th power of C(H+)*C(OH-)=10 to obtain the -12th power of C(H+)=2*10.

Similarly, if it is an acid solution, it must be calculated based on H+.

If the acid and base are mixed, the properties of the solution after the reaction will be calculated. Hope.

In the case of 25, it is.

Acetic acid is a weak acid and does not ionize completely, so the pH will be 5

The hydroxide species should be found first, and then the hydrogen ions according to the logarithm.

(1) At room temperature, increasing the temperature K will decrease, and pH 7 may be neutral.

2) Acetic acid is a weak acid pH 5

3) Less than this value.

When the solvents are different, the acidity and alkalinity are different.

Acetic acid is a weak acid that is not completely ionized in water. When diluted to 100 ml, its concentration becomes smaller, which promotes the ionization of acetic acid, and the total number of H+ in solution is more than at 1 ml, hence its pH 5

Because pure water at 100°C, the pH is about 6, but the water is still neutral. Because pH is affected by temperature.

The first reaction of carbon dioxide into the clarified lime water is:

The second reaction occurs when CO2 + Ca(OH)2===CaCO3 +H2O is introduced in excess.

2co2 +ca(oh)2===ca(hco3)2

After the excess CO2 is introduced into the Ca(OH)2 solution, the lime water will become clear after a period of time.

2co2 +ca(oh)2===ca(hco3)2

Excess CO2 converts calcium carbonate (poorly soluble in water) into calcium bicarbonate (soluble).

If too much is introduced, Mr. will become a solid calcium carbonate, and later, the calcium carbonate reacts with carbon dioxide to form calcium bicarbonate! Tolerable!

The amount of hydrogen ions in sulfuric acid (H2SO4) solution is twice the amount of sulfuric acid substances, when the amount of hydrogen ions in sulfuric acid solution is moles, the amount of sulfuric acid substances is moles.

From H2SO4, it can be seen that the ratio of hydrogen ions to sulfates is 2:1, and when the hydrogen ions are calculated to be moles, the sulfate is moles according to the ratio.

CH2Cl2 and CCL4 both contain polar bonds, both are SP3 hybrid orbitals, tetrahedral structure, but the four polar bonds of CCL4 are the same, the molecules are arranged in a positive tetrahedron, and the positive and negative charge centers overlap, so the molecule is non-polar, while in CH2Cl2 due to the difference between C-H and C-Cl, the molecular structure is deformed, it is not a positive tetrahedron, and the positive and negative charge centers are not together, so it is a polar molecule.

CO2 is sp hybridized and is linear, while H2O is sp3 hybrid (two electron pairs on the central oxygen atom each occupy a hybrid orbital, so it is sp3).

CH2Cl2 is a polar molecule.

Why is CO2 linear and H2O not? What are the rules?

It is related to the type of hybrid orbital.

It is related to the type of hybrid orbital.

CO2 has no lone electron pairs, H2O has two lone electron pairs, and it can be seen from the common electron pair mutual exclusion model that H2O is V-shaped and CO2 is linear. O=C=O,H-O-H,CO2 atoms have bonds and bonds, and H2O atoms have only bonds.

Solution: CuO+H2SO4=CuSO4+H2O

CuSO4 + BA(OH)2 = BASO4 (precipitation) + Cu(OH)2 (precipitation).

Therefore, an appropriate amount of barium hydroxide solution was added, filtered, and a mixture of barium sulfate and copper hydroxide was obtained.

Copper hydroxide is a blue flocculent precipitate.

Barium sulfate is a white precipitate.

So what you get is a mixture of these two precipitates.

Copper oxide reacts with sulfuric acid to form copper sulfate, while copper sulfate reacts with barium hydroxide to form a mixed precipitate of copper hydroxide and barium sulfate.

Copper hydroxide and barium sulfate are precipitated and cannot be separated by filtration.

The result is a mixture of copper hydroxide and barium sulfate.

The reaction of barium ions and sulfate is also a precipitation.