Chemistry questions are questioned, a few chemistry questions are in doubt, speed helps...

Carbonic acid is H2CO3, which is a weak acid, and nitric acid is Hno3, which is a strong acid with strong oxidizing properties.

For acid-base indicators, set Hin to be an acid indicator and in- to be a base indicator.

Then phenolphthalein hi == h+ +in-

Colorless red.

After adding the alkali, the alkali neutralizes the acid, the equilibrium shifts to the right, and the solution is in, which is red.

The smaller the pH, the more acidic the solution is, because pH = -log (hydrogen ion concentration) The acidity and alkalinity are compared by the concentration of hydrogen ions and hydroxide ions. This sentence is considered true if it is considered true in the case of equal temperature, but it cannot be considered true when the temperature is different, such as.

In pure water at 100 degrees, the pH is equal to 6, but it is neutral, and at 25 degrees Celsius, the pH is 6, it is an acidic solution.

Carbonate H2CO3 is a weak acid.

Nitric acid Hno3 is a strong acid.

Phenolphthalein, like most indicators, is an organic acid that, when reacted with H+, produces new compounds with specific colors. Therefore, the pH value can be indicated.

Because each indicator has a different PKA value, i.e., a different range of reactions, different indicators have different ranges.

The calculation of the various properties of indicators is a part of the second year of analytical chemistry.

This is the chemical formula of phenolphthalein (see web link). Purple litmus is a mixture extracted from lichens and has no fixed chemical formula.

pH is a quantitative characterization of the acidity and alkalinity of the solution, pH = -lg hydrogen ion concentration, the stronger the acidity of the solution, the smaller the pH.

Carbonate H2CO3 is an acidic solution, but it is a weak acid

Nitrate Hno3 is one of the four strong acids

Colorless phenolphthalein turns red when it encounters alkali (it does not change color when it encounters acid and salt), and purple litmus turns red when it encounters alkali (it turns blue when it encounters alkali), so naoh turns red when it encounters colorless phenolphthalein, and turns blue when it encounters purple litmus

The lower the pH, the more acidic the solution is

Carbonate H2CO3 is a weak acid.

Nitric acid Hno3 is a strong acid.

Colorless phenolphthalein is reddened when it encounters an alkaline solution...

At a certain temperature, the lower the pH, the more acidic it is, and rightly.

Carbonate H2CO3 is a weak acid.

Nitric acid Hno3 is a strong acid.

NAOH can make colorless phenolphthalein red, you are mistaken, it is the acid that turns red when it meets litmus.

The lower the pH, the more acidic the solution is not necessarily stronger. The temperature should be constant.

Answer: Carbonic acid and nitric acid are inorganic acids.

NaOH can make colorless phenolphthalein reddened The discoloration pH range of phenolphthalein is: 8 10 Acid does not change color when phenolphthalein.

The lower the pH, the more acidic the solution is.

Carbonate H2CO3 is a weak acid, which is an acid, but it is not a strong acid.

Nitric acid is Hno3 and is a strong acid.

Phenolphthalein turns red when it encounters alkali.

pH is a quantitative characterization of the acidity and alkalinity of a solution, and the more acidic the solution, the smaller the pH.

1.2Fe3+ +Cu=2Fe2+ +Cu2+ (no trim, to follow conservation of charge).

Clo- +SO2+H2O=H+ +Cl-+SO42- (This is a redox reaction, and the valence can only be carried out when the valency increases or decreases.) ）

2。C1 = C2>C3, (FeCl3 solution with pH 3 and Na2CO3 solution with pH 11 both undergo hydrolysis, which is essentially equivalent to water ionization, that is, promoting ionization, so the hydrogen ionized by water is the same).

3.NO2 is partially converted to N2O4 on its own, so the total number of molecules contained is less than.

4.1mol C13H28, carbon-carbon bond 12, hydrocarbon-28C13H28 with the number of covalent bonds.

5.The carbon tetrachloride solution of bromine reacts with cyclohexadiene, and the bromine fades.

Benzene and carbon tetrachloride are both organic solvents, so there is no obvious phenomenon when they are added.

1 The ion equation for corrosion of the circuit board with ferric chloride solution: Fe3+ +Cu=Fe2+ +Cu2+

Untrimmed, left and right anions and cations are not conserved should be 2Fe3+ +Cu=2Fe2+ +Cu2+

SO2:2clo- +SO2+H2O=2HCO+SO32- is introduced into sodium hypochlorite solution

Because hypochlorous acid has strong oxidizing properties and SO2 is reducible, redox reactions will occur, and NA+ Cl-+SO42-+H2O should be generated.

2. At room temperature, the concentrations of H+ ionized by water in FeCl3 solution with pH 3, Na2CO3 solution with pH 11 and hydrochloric acid with pH 3 are C1, C2, C3, C1> C2>C3

C1, because Fe will be hydrolyzed, it is all ionized by water, C(H+)=10 (-3).

c(h+)=c(oh-)=1*10 (-3) for c2 ionization should be fine, right? Because some of the water ionized out H+ and CO32- to form HCO3 - too.

C3 ionization out of oh- is 10 (-11), because kw = 10 (-14), and where c (h+) is ionized by hydrochloric acid is 10 (-3), according to the formula of kw, c (oh-) = 10 (-11), water ionization oh- is as much as h+, so c (h+) = 10 (-11).

So c1=c2>c3

3 Under the standard condition, the total number of molecules contained in 23gNO2 gas is:

.This one thinks you're right. See if the title says it's in the air? What is not said is that the topic is not rigorous.

4. What is the number of covalent bonds in a molecule at room temperature and pressure?

Because I'm confused by your equation, I'll just say the method: write out the formula first, and then see how many mols there are, how many covalent bonds are in each, such as a, and then multiply the amount of matter to the total.

5. How to identify the two colorless liquids of cyclohexadiene and benzene with the repaired carbon tetrachloride solution?

You pour it in and you're good to go. The first one faded.

The second one doesn't fade. It is necessary to add fe as a catalyst to fade.

The first charge in 1 is not conserved, and in the second equation hypochlorous acid and sulfurous acid are both weak acids, and ion 2 should be c2> c3>c1

3 is true even if it is not the standard condition, 23 grams is.

4 There are 4*13=52 covalent bonds in a molecule, then it is equal to, so the total number of covalent bonds that are is one.

5-cyclohexadiene can discolor bromine, while benzene cannot.

It's so hard.

1.Wrong, because the ions on both sides are not conserved.

You have to remember that the number of electrons gained by the oxidant should be equal to the number of electrons lost by the reducing agent, so 1 should be 2Fe3+ +Cu=2Fe2+ +Cu2+ Hypochlorous acid has strong oxidizing properties, oxidizing SO32- to SO4H2O+2Cl-+SO2=(SO4)2-+2Cl-+2H+>C2=C3, because the OH of C2 has 10-3, so the H+ of water in No. 2 is only 10-11

The hydrochloric acid of No. 3 is completely ionized, which inhibits the ionization of water, and the H+ concentration of water ionization is the same as that of OH- in water, which is only 10-11

It will become N2O4 in the air, so there are fewer molecules in 23gNO2.

4.Each c generates 4 covalent bonds, again because two atoms share a bond here.

So there is a covalent bond.

5.Ethylene has unsaturated carbon, and the carbon tetrachloride solution with bromine added will undergo an addition reaction and then fade.

Benzene does not fade.

1.The first one is unbalanced, which does not follow the conservation of charge, and the coefficient is sufficient; Second, since hypochlorous acid is a weak acid, it cannot be ionized.

The total number of molecules contained in the NO2 gas is , the amount of the substance of the gas is divided by volume is tridecane under the standard condition, and each C atom forms four covalent bonds with hydrogen, and the substance is , then the covalent bond is 13*4* = pcs.

At the level of a brother, I can only help you with this.

1. The left and right charges are not conserved. The gas symbol is not marked.

2、c2>c1>c3

I haven't watched it for a long time.

You don't have to follow the topic. The meaning of the title is that there is h2

Don't dwell on that.

Scoring is the most important thing.

Sometimes the principle is learned at university.

What we learned in high school is to make us better remember these equations, and maybe some of them are wrong. But the teacher is just there for you to remember.

CH4+CO2===2CO+2H2 is the total reaction CH4===C+2H2 and C+CO2===2Co added up by the sum of two reactions

Think of the equation for water and gas.

So2 can be added to water to form H2SO3, so if there is enough water, it is possible to generate H2SO3, but in the middle school chemistry range, H2SO3 is generally treated as a weak acid, and the room temperature is unstable, so S02 is still generated

ps: I was a representative of chemistry class in high school, and the landlord believed me :)

Hydrochloric acid is just an aqueous solution of HCl. A small amount of water is dropped into SOCL2. The water is consumed by the reaction.

So the resulting HCl can only escape in the form of a gas. As for sulfurite, the same is true. Sulfurous acid decomposes easily.

and can only exist in solution.

Sulfurous acid is unstable.

h2so3=so2+h2o

If you do it the way you do:

SOCl2+2H2O==SO2 +2HCl +H2O can eliminate an H20

That is, SOCl2 + H2O ==SO2 + 2HCl

SOCL2+H2O only has 2 oxygen ions, why don't you find one more, and one more hydrogen.

(1) Not necessarily, Na is more reducible than Al, but it can only lose 1 electron (is it wrong, the reducing agent is a loss of electrons).

2) Not necessarily, Fe2+ can lose electrons to become Fe3+

3) Not necessarily, H2O in H is +1 valence, the most **, but water is not a strong oxidant.

1) False: The sodium reaction only loses one electron, and the aluminum reaction loses three electrons, but sodium is highly reducible with aluminum.

2) FalseFe2+ can lose electrons and be used as a reducing agent.

3) False: Oxygen has no valence, so oxygen is a compound of ** element, but it is not strongly oxidizing.

1.No, sodium bicarbonate is generated.

3.The reaction between sodium and copper sulfate solution is actually sodium first reacting with water to form sodium hydroxide, and then reacting with copper sulfate. Whereas, iron is directly displaced with copper sulfate. The essential difference is due to the different activity of iron and sodium, with sodium being much more active than iron.

4.No, silicon, for example, is also more special, and will be learned later. The oxide of silicon can also react with alkali and can also react with hydrofluoric acid (only hydrofluoric acid).

Remember? Hope it helps

1 Sodium bicarbonate is generated, the reason is that sodium bicarbonate is called sodium carbonate and has low solubility.

2 Excess carbon dioxide is introduced.

3 The former is essentially sodium reacts with water to form sodium hydroxide, and sodium hydroxide reacts with copper sulfate The latter is a simple displacement reaction.

4 is not, like some amphoteric substances elemental oxides can react with bases. That's all.

First floor: Finally, I got it wrong, silicon oxides can only react with hydrofluoric acid.

Only answer question 4, and the first three questions are answered very well on the first floor.

Question 4 should be zinc. It is similar to aluminum, and both oxides and hydroxides are amphoteric (acid-base amphoteriors).

There is also a mistake on the third floor, SiO2 can also react in concentrated alkali or hot alkali, and the reaction is slow and the equilibrium constant is small.