Ammonia prac method question

[dekoyl]

An alternative procedure for determining the amount of ammonia in Cloudy Ammonia is to have two 20.00 ml aliquots of standard 0.100 M HCl put into the titration flask with one 20.00 ml aliquot of dilute (approximately 0.1 M) Cloudy Ammonia solution. The excess HCl would then be titrated against standard 0.1 M sodium carbonate solution using methyl red as an indicator. What advantages are there to this alternative method?

I can't think of any advantages. Not understanding this question too well.

Thanks.

[lacoste]

What chapter is this in ? //topic?

[dekoyl]

Topic of titration. It's not from textbooks.

[Wizard]

Ammonia is volatile. Hence, using a direct titration with HCl would not produce an accurate volume, and therefore, an accurate concentration. A back titration overcomes this problem.