influence of HCl on the aqueous solution of H2S

[spps]

Please help.
How to present the influence of HCl on an aqueous solution of H₂S?

[ChenBeier]

How is H₂S dissociated in water? Equation please. What happend with the equlibrium if H+ is added?

[spps]

aqueous solution of H₂S:
H₂S + H₂O → H₂SO₄


2HCl + H₂SO₄ → Cl₂ + SO₂ + 2H₂O

Are such equations correct?

[ChenBeier]

No

Here it is asked what happend if you dissolve H₂S in water. There is no Oxidation to sulfuric acid.
Write the dissolving and dissociation equation
This is expressed as an equilibrium.
What happens if you add H+ to this equilibrium

[spps]

dissociation equation H₂S + H₂O -> H₃O(+) + HS(-)

[ChenBeier]

Yes correct. So what happens if HCl will be added.

[spps]

HCl + HS(-) + H₃O(+) -> Cl(-) + H₂S(-) + H₃O(+)

[ChenBeier]

It is H₂S not H₂S(-). It means the H₂S will be expelled. It get more stunk.

[spps]

is this the correct form of the equation ?

HCl + HS(-) + H₃O(+) -> Cl(-) + H₃O(+) + H₂S↑

[spps]

Are the following description and drawing correct?


Reaction on wet indicator paper
H₂S + H₂O = HS + H₃O

Observations:
There is gas coming out of the test tube with a characteristic smell.
Universal test strip turns red when wet.

Conclusions:
The gas that evolves is hydrogen sulfide

[ChenBeier]

This could be misinterpretation, because also HCl fume turn the paper red. Better is to use lead acetate paper which turns Black by PbS.


The chemical reaction could be simplyfied.

H₃O+ + HS- => H₂S + H₂O Adding HCl
Vise versa reaction on pH paper.

[spps]

Thank you very much!

[spps]

Reaction on lead acetate paper that turns black by PbS.

It's OK?
H₂S + (CH₃COO)₂Pb → 2CH₃COO + PbS↓

[ChenBeier]

What about the H from H₂S

[spps]

H₂S + (CH₃COO)₂Pb → 2CH₄COO + PbS↓