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Chemistry Forums for Students => Undergraduate General Chemistry Forum => Topic started by: defencegrid on January 03, 2017, 11:38:40 PM

Title: Adding HCl to Iron (III) Chloride
Post by: defencegrid on January 03, 2017, 11:38:40 PM

Hi.  I have a book that says to prepare a solution of Iron (III) Chloride you need to dissolve the solid in water and add 5ml of concentrated HCL and make up to 1 litre with water.  Just wondering what is the purpose of the HCL?

Iron (III) Nitrate it similar, it says to add 5ml of 2M Nitric Acid and for Iron (III) Sulphate it says to add 0.1M Sulphuric Acid.   

Title: Re: Adding HCl to Iron (III) Chloride
Post by: AWK on January 04, 2017, 12:56:12 AM

Fe(III) salts easily hydrolyse. Acids prevent from hydrolysis.

Title: Re: Adding HCl to Iron (III) Chloride
Post by: defencegrid on January 04, 2017, 02:41:03 AM

Quote from: AWK on January 04, 2017, 12:56:12 AM

Fe(III) salts easily hydrolyse. Acids prevent from hydrolysis.

I see.  So how does the acid prevent the hydrolysis?

Title: Re: Adding HCl to Iron (III) Chloride
Post by: AWK on January 04, 2017, 02:49:10 AM

Wite equation of hydrolysis of Fe(H₂O)₆³⁺ ion