You perform the following titration: You placed 35 mL of H2S in a flask and placed it under a buret. The buret contains 0.243M Sr(OH)2 and you are going to titrate the H2S with the base. You titrate until the color changes. At that point, you record that you used 10.15mL of base to titrate. Calculate the unknown molarity of the H2S.

Question

You perform the following titration:  You placed 35 mL of H2S in a flask and placed it under a buret.  The buret contains 0.243M Sr(OH)2 and you are going to titrate the H2S with the base.  You titrate until the color changes.  At that point, you record that you used 10.15mL of base to titrate.  Calculate the unknown molarity of the H2S.

DrBob222 · Answer

Did you make up this problem or have it handed to you? However it was done you should recognize that H2S is a gas and isn't about to stand around in a titration vessel and wait to be titrated. Anyway, in the spirit of the problem here is how it is solved.

H2S + Sr(OH)2 ==> 2H2O + SrS
mols Sr(OH)2 = M x L = ?
Look at the equation and see that mols Sr(OH)2 = mols H2S
Then M H2S = mols H2S/L H2S.