A topic in chemistry will be seen by the person for himself, and the chemistry question in the secon

Option C The oxidation of Fe3+ is stronger than that of Cu2+, and the elemental iron first reacts with iron ions, and then reacts with copper ions after the iron element has a surplus.

In item A, SO32- is more reducible than I-ions, so chlorine reacts with SO32- first.

In item B, the degree of electrolysis of Al(OH)3 produced by the first step of ALO2- reaction with hydrochloric acid is less than that of CO32- in the first step of reaction with hydrochloric acid to form HCO3- (the electrolyte is dissolved in solution and is called electrolysis. The degree to which a substance can be electrolyzed is called "degree of electrolysis") is less than the Al(OH)3 produced by the first step of the reaction between AIO2- and hydrochloric acid, so the hydrochloric acid reacts with ALO2- first. (It can also be seen from the reaction alo2- +HCO3- +H2O = CO2- +Al(OH)3) that a stronger electrolyte reaction can produce a weaker electrolyte).

In item D, the principle is the same as in item B, and the degree of electrolysis of Al(OH)3 produced by the first step of the reaction of Al3+ with sodium hydroxide is less than that of NH4+

The degree of electrolysis that reacts with sodium hydroxide, so hydrochloric acid reacts with NH4+ first. (It can also be seen from the reaction Al3+ +3NH3·H2O = AL(OH)3( )3NH4+).

Attached: The order of chemical reactions:

1. When acid, alkali and salt are mixed, reactions can occur between acid and salt or between alkali and salt

1) If there is a redox reaction between them, consider the redox reaction first, and then the metathesis reaction.

2) Metathesis reaction, first consider the acid-base neutralization reaction, and then consider the reaction between acid and salt or between base and salt.

3) If multiple similar reactions can occur, the weaker the electrolysis of the product or the smaller the solubility of the precipitate, the reaction will be carried out first.

2. When adding a solution or introducing gas into the suspension, the reaction with the solution should be considered first, and then the reaction with the solid in the system.

3. The essence of the redox reaction is the reaction of electron transfer between reactants, so the stronger the ability of the oxidant to obtain electrons, the stronger the ability of the reducing agent to lose electrons, and it is easier to transfer electrons between the two strong, and the strong is preferred. That is, the more oxidizing or reducing pre-reaction.

In the following solutions with ion concentrations of mol l, after a substance is added (or introduced), the reaction sequence is as follows.

A In the solution containing I-SO32-, chlorine gas is continuously introduced I-, SO32-: SO32-, I-, sulfite is highly reducible.

b Hydrochloric acid CO32- AIO2- :AIO2- CO3- is continuously introduced into the solution containing AIO2- CO2-, and the acidity of aluminum hydroxide is weak.

c Iron powder is continuously introduced into the solution containing Fe3+ Cu2+, Fe3+, Cu2+: Fe3+, Cu2+, and the oxidation of ferric iron is weak.

DAdd caustic soda solution to the aqueous solution containing AI3+ NH4+, NH4+ AI3+: AI3+ NH4+, ammonia and aluminum ions will react to form aluminum hydroxide and ammonium ions.

There is the following reaction: 3NO2+H2O=2HNO3+NO, so if there is 3x molNO2, then X mol NOs are generated, because the original 10 is 3x, and there is more X, it becomes 5, then there is 10-3X+X=5

The solution is x = so there is no2 mol, no mol

The volume ratio is equal to the ratio of the amount of matter and is 3:1

I hope it helps you a little, o( o don't understand and ask again!

3NO2 + H2O == 2HNO3 + NO, so 3 volumes of NO2 are formed after the reaction of 1 volume NO

So there is: 1 3 v(no2) +v(no) = 5ml and because: v(no2) +v(no) = 10ml solution v(no2) = , v(no) =

So the ratio of the volume of no2 to no = 3:1

Analysis: This question is a question type in which nitrogen oxides are dissolved in water.

3NO2 + H2O = 2HNO3 + NOV (change value before and after volume reaction reaction).

3 2x （10-5）mol

x =v(no)= 10mol –

According to Avogadro's law, it is inferred that at PV = n RT at the same temperature and pressure, the ratio of the volume of the two gases is equal to the ratio of the quantity of matter.

v(no2): v (no) = 3:1

12x/(12x+y)=

x/y=112x+y=26

Molecular weight: 26 Simplest formula: C2H2 Molecular formula: C2H2

Molecular weight: 26 Simplest formula: C2H2 Molecular formula: C2H2

Relative molecular weight = 2 * 13 = 26

The substance is found to be acetylene, the simplest form ch

c2h2

Individuals calculated the unknown hydrocarbon as CH4, and the analysis is as follows:

If the final solid is all Na2CO3, then the mass should be, but the result is greater than it, first calculate that for a molna atom, the mass of sodium carbonate is 53 (106 Li and 2), 40 when sodium hydroxide exists, and 84 when sodium bicarbonate exists, so the final solid judgment is sodium carbonate and sodium bicarbonate, let the amount of sodium carbonate be x 2, and the equation can be obtained from the conservation of the amount of sodium element substance: 106x 2+84 ( The solution is x=, and the amount of sodium carbonate is , The amount of sodium bicarbonate is 2NaOH+CO2==Na2CO3+H2O: H2O+Na2CO3+CO2==2NaHCO3

From the above two formulas, it can be seen that there are CO2 participating in the second reaction, and the first one is definitely participating in the total CO2. Therefore, the gas (calculated by volume) contains atoms, and one is ethane (1mol contains two molc), then the other can only be methane. Then set ethane amol, methane (, 2a+, a=, which tremor methane, .

I don't know what to do?

The answer is wrong, and the solution process of nkzybc is correct, that is, the tung-based volume ratio of methane to ethane is: 2:1. The methane volume fraction is, and the ethane volume fraction is:.

Let's not consider the ionization of water molecules:

NaOH solution with pH 8 C(H+) = 10 -8mol L

NaOH solution C(H+) with pH 10 = 10 -10mol L

It is equivalent to finding the middle number of 2 data.

The value is 1 2(10 (-8)+10 (-10)) mol l, which matches option a.

Option b: (10 (-8)+10 (-10)) 10 (-8), the middle number of the two numbers is greater than the maximum, the difference is too big, exclude.

Option C: This option is even more outrageous, the value is less than 0, indicating that C(OH-) 1 mol L, excluded.

Now that's all A and D left

Take the solution with pH = 10 as the reference object, and the equal volume of the solution is mixed to dilute the solution, then the ionization equilibrium of the water molecule is promoted, and the equilibrium is moved positively, then the final H+ concentration is greater than the original H+ concentration of 10 (-10).

The value of option a: 1 2 (10 (-8) + 10 (-10)) = 1 2 (100 * 10 -10 + 10 -10) = (101 2) *10 -10

dOption 2*10 (-10).

Both are greater than 10 (-10), but option A is much larger. The A value is the value of the ionization of the water molecule without change, and the D value is the value of the ionization of the water molecule that cannot be ignored.

Because the order of magnitude of pure water hydrolysis is 10 -7, the ionization energy of water molecules plays a decisive role in both extremely dilute alkaline solutions.

So, the answer should be d

The H+ in both solutions is ionized by water at concentrations of 10 -8 mol l and 10 -10 mol l

OH- is different, the OH- ionized by water is also 10 -8 mol L and 10 -10 mol L, and its concentration is equal to the upper value, and the concentration of OH- ions ionized by NaOH is (10 -6 - 10 -8) mol L and (10 -4 - 10 -10 -10) mol L

D is right.

Because of the pH difference of 1, in fact, the concentration difference is 10 times, which is logarithmic. pH 10 is 100 times greater than pH 8 concentration, mix in equal amounts, equivalent to 1 times dilution.

Then, the concentration of OH- is considered to be 5E-5mol L, so the vast majority (close to 100%) of H+ closest to DOH- is NaOH. H+ is all about water, and I hope it helps you

It's not all water and electricity. OH- is mainly from NaOH, and H+ is completely ionized from water.

When Alcl3 and MgCl2 are added to 100ml with x and y mol respectively, m (NaOH solution) = 127gn (NaOH) =

m（naoh）=

The quality score is out.

3x+2y=

4x+2y=

X and Y came out ......Then you know everything, and the third question can come out. It is one to two with magnesium precipitation, one to three with aluminum, the amount of substance.

The picture is in **, and it is not easy to do without a picture.