[freddo]

I have sample H2S (l) with concentration 60%, and i must proofed it's correct 60% or not?
I'm very confused how first step must i do? 

and what way i must to do? if the way must by titration, what kind of titration?
and please some body give the procedures to  check that samples.

thank you

[woelen]

Are you sure you have H2S? H2S is a gas, with a strong smell of rotten eggs, which only is moderately soluble in water. At low temperatures you may get a solution with a percent or two of this gas, but 60% definitely is not possible.

Let us know what you really have, and then we may be able to help you further.

[sanjay.u]

If you measure the concentration of H2S then you have to use H2s analyser which uses photometric principle. In this type of analyser there is a source side UV lamp of Cadmium make which emits light of ultraviolet range of 200 nm to 400nm and detector is usually photo diode with optical filter of 228 nm in between. Sample gas is passed through sample cell with Glass window. In which one side is UV lamp and other side is optical filter and detector. H2s is absorbs 228 nm of light of UV and absorption depends on the concentration of gas. If concentration is high then it will absorbs more light. Remaining light which is not absorbed will pass through optical filter which will allow to pass 228 nm light and it will be converted in to voltage by photo detector. this way you can measure concentration in terms of voltage signal . this signal is processed in electronics board and you will get reading on the display.

[gkdmaths]

How about trying a simple potentiometric titration of sulfide using silver nitrate, a Cu/CuSO4 reference electrode and some silver wire for a working electrode? It offers precision, is quick and simple to perform. This is an excellent titration for other halogens, too - so pay attention to your reduction potentials.

/gkd