Why does NaCl absorb HCl but not Cl2

You are saying that chlorine gas is introduced into saturated NaCl to remove HCl, first of all, HCl is very soluble in water, and it is very easy to absorb when introduced into water.

But why use NaCl.

That's because the addition of NaCl increases the concentration of Cl-.

Cl2 will also be soluble in water, and the following reaction occurs in small amounts: Cl2 + H2O = HClL + (H+) + Cl-

An increase in the concentration of Cl- can shift the equilibrium of this reaction to the left! This reduces the amount of Cl2 dissolved in water and reduces the loss of Cl2.

NaCl is for Cl2 and has nothing to do with HCL!

HCl can be dissolved in water in large quantities, while Cl2 reacts reversibly with water. When there are many chloride ions in the water (saturated NaCl solution), the chlorine gas basically does not react with the water, so HCL can be removed

For water, Cl2 is a weak electrolyte, and HCl is a strong electrolyte, when these two gases are brought to the saturated NaCl solution, there will be a homoionic effect, so that the solubility of chlorine gas is reduced, almost insoluble in water, NaCl solubility in water is reduced, crystals are precipitated, and HCl is soluble in water, but the solubility is also reduced. There are 2 cases of the homoionic effect:

1. In the solution of the weak electrolyte, if a strong electrolyte containing the same ions as the weak electrolyte is added, the ionization degree of the weak electrolyte will be reduced.

2. In the electrolyte saturated solution, adding a strong electrolyte containing the same ions as the electrolyte will also reduce the solubility of the electrolyte.

It can also be explained from the chemical shift equilibrium: Cl2 + H2O = reversible HCl+HCl, due to the saturation of the solution, less water, and the presence of NaCl makes the equilibrium move backwards, so that chlorine almost does not react with water.

Chlorine is also soluble in saturated NaCl solution, but much less dissolved. Originally, the amount of chlorine dissolved in water is not large, and the dissolved volume ratio is about 2 times, so that chlorine can be collected with saturated salt water, and the solubility in HCL is much reduced in salt water, but the volume ratio of HCL dissolved in water is about 500 times, even if it is only dissolved by 1%, there are 5 volumes.

cl2+h2o==hcl+hclo;

2hcl+na2co3==2nacl+h2o+co2↑;

HCO+NA2CO3==NAHCo3+NACLOsNote: Chlorine gas is introduced into sodium carbonate solution, which is understood as first reacting with water to form hydrochloric acid and hypochlorous acid, which are then reacted with sodium carbonate;

It should be noted that hypochlorous acid is less acidic than carbonic acid and stronger than bicarbonate ions, and it cannot react with sodium carbonate to form CO2

It is also simple to be together, but it should conform to the proportion, like HCL and HCL are 1:1 relationship;

1 Formula 2) + (2 Formula) + (3 Formula 2), and then eliminate the same, get:

2cl2+3na2co3+h2o==2nacl+2naclo+2nahco3+co2↑

The ratio of each thing is different, the degree of reaction is different, and there are water molecules in the solution.

Behavior: HCl gas is soluble in water.

In fact, they are all dissolved, but the chlorine gas dissolved very little in sodium chloride According to the ionization balance, chlorine dissolution and water will ionize chloride ions, and the concentration of chloride ions in saturated brine has reached saturation, and the concentration is also very large, so according to the principle of equilibrium movement, it is difficult for chlorine to continue to be ionized, and it can not continue to dissolve, so chlorine is collected by the saturated brine method.

Moreover, the solubility of chlorine is proud, with a ratio of 1:2 (less in saturated sodium chloride) while HCl is soluble in water, and the ratio is about 1:10. I forgot the specifics) so it is generally collected with a saturated sodium chloride solution.

It is possible to use a saturated solution containing chloride ions).

The reaction conditions are different, and the products are different, in this case because of the reaction rate.

At lower temperatures, the rate of Naclo3 generation is slower, so it is rate controlled, so that the reaction products stay in the Naclo stage;

If the Naclo solution is heated, a further reaction is taken to form sodium chlorate:

3Naclo = 2NaCl + Naclo3 It is right to say that in this example, the degree of disproportionation reaction is temperature dependent.

The degree of disproportionation reaction is independent of the base concentration. But the rate of disaggregation is related to the base concentration.