Why is the conservation of protons in sodium bicarbonate solution minus carbonate

This is a difficult problem that most students need to overcome in the second year of high school, which involves the problems of hydrolysis and ionization. I'll explain this way to see if you understand, and I hope it can help you.

When understanding the conservation of protons, I often say that it turns out that water ionizes as many hydrogen ions as hydroxide ions, which is very understandable. h2oh+

OH- Then the hydrogen ions or hydroxide ions in the solution react with the weak ions in the salt to form the corresponding weak acid or weak base, resulting in the hydrogen ions and hydroxide ions are no longer equal, and the solution is acidic or alkaline. Then you can use the method of "tracking" when you write about the conservation of protons in reverse, who "h+.""Or "oh-"** just find it back and add it if you use it.

For example, the hydrolysis of Na2CO3 is in two steps, CO32-+H2O

hco3-+oh-

hco3-+h2o

h2co3+oh-

It's obvious. CO32 - to the last.

HCO3 and.

The H+ consumed by H2CO3 is a double and a 2x relationship, respectively, so the final conservation relationship is: c(oh-=c(H+

c(hco3-

2c(h2co3)

Then the hydrolysis of NaHCO3 only.

hco3-+h2o

H2CO3+OH- but at the same time there is ionization of HCO3-.

i.e.: HCO3-

co32-+h+

This step is the excess H+, and the excess is equal to the amount of CO32- produced, of course, the extra H+ should be subtracted at the end, which is equivalent to subtracting the concentration of CO32-. Namely:

c(oh-)=c(h+

c(h2co3)

c(co32-)

Carbonate is made up of bicarbonate.

Ionization of one H+ obtains, the ionization of H+ from water in solution is equal to the total number of protons minus the ionization of bicarbonate out of H+

Conservation based on protons alone cannot subtract carbonate.

Sodium carbonate. Step-by-step hydrolysis, sodium bicarbonate.

One-step hydrolysis, hydrolysis of the ion prescription is as follows:

CO32-+H2O = HCO3-+OH-HCO3-+H2O = H2CO3+OH- According to the ionic equation, a mixed solution can be obtained.

The proton guard clump finch wheel is constant:

c（oh-）=c（h+）+c（hco3-）+2c（h2co3）

Conservation of charge refers to all cations in solution.

The total amount of positive charge carried by the anions is the same as all the anions.

The total amount of negative charge is equal.

C(Na+) C(H+) C(CH3COO-) C(OH-) The material is conserved. Refers to the conservation of certain key elements in the solution, still in sodium acetate.

For example, where ch3coo is conserved:

C(Na+) C(CH3CoO-) C(CH3Cooh) Proton conservation refers to the total amount of hydrogen ions and hydroxide ions produced by the ionization of hydroelectric swims in the liquid is equal to the total amount of hydroxide ions. In the above solution:

C(OH-)=C(H+) C(CH3Cooh) in sodium carbonate solution:

C(OH-)=C(H+) C(HCO3-) 2C(H2CO3) Description: H in HCO3 and H2CO3 are both from the ionization of water, and the ionization of H in water must be ionized at the same time as OH

Conservation of charge: C(H+)+C(Na+)=C(OH-)+C(HCO3-)+2C(CO32-).

Conservation of materials. c(na+)=c(hco3-)+c(co32-)+c(h2co3)

The whole or the spring acacia theory is two formulas to obtain the conservation of protons: the forest cavity c(h+)+c(h2CO3)=c(oh-)+c(CO32-).

Summary. First of all, acid ions are not written to be conserved by protons.

The reason is simple. Because the conservation of protons is the use of hydrogen ions ionized by water = hydroxide ions ionized by water, if there are other ions ionized to produce hydrogen ions or the concentration of hydroxide ions in the solution is very confusing, if you have to write it and understand it as the conservation of protons, it can only be understood by the conservation of charge and the conservation of materials, which is why you see that there is no bicarbonate because it is reduced by you in the process of subtraction.

Sodium bicarbonate proton conservation why is it not counted as bicarbonate produced by carbonate hydrolysis.

First of all, the reason why acid ions do not write proton conservation is simple. Because the conservation of protons is the use of hydrogen ions ionized by water = hydroxide ions ionized by water, if there are other ions ionized to produce hydrogen ions or the concentration of hydroxide ions in the solution is very confusing, if you have to write and Huaiyan and understand it as the conservation of protons, it can only be understood by the conservation of charge and the conservation of materials, which is why you see the formula without bicarbonate because you are reduced in the process of subtraction.

I've read this three times, and this is the example our teacher gave that I can write about.

Then you accept me.

Okay, then I'll do it all over again.

If you really understand this aspect, you can understand my problem by looking at what I wrote.

Well, this method I know, I don't want to push the conservation of protons with charges and materials. I feel like I can come up with it normally.

Then you can accept this method.

Well, you're the first human I've ever encountered, everyone else is copying, and my problem is that I think we should consider bicarbonate ionization to generate dust in the water of the lytic slippery fluid to let the brigade solve.

Isn't carbonate hydrolysis or hydrolysis into bicarbonate, and the original solution doesn't have bicarbonate ions?

Didn't you go back like this?

This can be obtained by the conservancy-of-charge and material-dependent relations.

NaHCO3 solution.

C(H+)+C(Na+)=C(HCO3-)+2C(CO32-)+C(OH-) Charge Conservation}

C(Na+)=C(HCO3-)+C(CO32-)+C(H2CO3) {Conservation of Materials}

Subtract the two formulas to give C(H+)+C(H2CO3)=C(CO32-)+C(OH-) This formula is called conservation of protons.

The conservation of protons in solution means that the concentration of H+ and OH- produced by the ionization of water is equal.

Sodium bicarbonate is both ionized and hydrolyzed in solution. The ionization equation is:

nahco3=na+ +hco3-

hco3-﹤=﹥h++co32-

Hydrolysis ion equation:

HCO3 - +H2O = H2CO3 + OH - Proton conservation of sodium bicarbonate can be obtained according to the above description:

C(OH-)=C(H+)+C(H2CO3)-C(CO32-)Note: 1. Because the concentration of hydrogen ions generated by ionization of bicarbonate ions is equal to the concentration of carbonate ions. Since the hydrogen ion contains H+ from the ionization of bicarbonate ions, it is necessary to subtract the carbonate ions formed by the ionization of bicarbonate ions.

2. The concentration of hydrogen ions generated by water ionization = the concentration of hydroxide ions generated by water ionization;

3. Each mole of bicarbonate ions is hydrolyzed and combines 1 mole of hydrogen ions, so the carbon dioxide concentration generated needs to be added.

Conservation of charge: C(H+)+C(Na+)=C(OH-)+C(HCO3-)+2C(CO32-).

Conservation of materials: C(Na+)=C(HCO3-)+C(CO32-)+C(H2CO3).

Sodium bicarbonate is not conserved by protons.

The so-called conservation of protons refers to the conservation of H2O ==H+ +OH- because NaHCO3 itself ionizes a part of H+, so the concentration of Oh- is not equal to the concentration of H+.

For example, Na2CO3 is conserved.

c(oh-)=c(h+)+c(hco3-)+2c(h2co3)