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Chemistry Forums for Students => Analytical Chemistry Forum => Topic started by: nisha1 on July 16, 2009, 02:06:37 AM

Title: Ca and Mg determination by EDTA method
Post by: nisha1 on July 16, 2009, 02:06:37 AM
Why we prepare Mg-EDTA indicator solution?
Why ca'nt we only use EBT indicator?
Can you provide me with actual principle behind the usage of Mg-EDTA indicator.
I have used ammonia buffer to maintain pH=10
Title: Re: Ca and Mg determination by EDTA method
Post by: Borek on July 16, 2009, 03:19:21 AM
http://www.titrations.info/EDTA-titration-water-hardness
Title: Re: usage of EDTA-Mg indicator for determination of Ca and Mg ions in Commercial
Post by: nisha1 on July 17, 2009, 12:38:44 AM
Sir, actually i want to know the usage of EDTA-Mg indicator for determination of Ca and Mg ions in Commercial milk powder.
Is it appropriate to use Mg-EDTA indicator with the sample having Mg ions in it (like milk powder)?
If yes, then will it not interfere with the concentration of Mg ions already present in the sample?
Title: Re: Ca and Mg determination by EDTA method
Post by: Borek on July 17, 2009, 02:31:50 AM
I believe your answer is answered on the page linked. Have you actually read it?
Title: Re: usage of EDTA-Mg indicator for determination of Ca and Mg ions in Commercial
Post by: nisha1 on July 17, 2009, 02:53:37 AM
Quote from: nisha1 on July 17, 2009, 12:38:44 AM
Sir, actually i want to know the usage of EDTA-Mg indicator for determination of Ca and Mg ions in Commercial milk powder.
Is it appropriate to use Mg-EDTA indicator with the sample having Mg ions in it (like milk powder)?
If yes, then will it not interfere with the concentration of Mg ions already present in the sample?
sorry for the cross post but in my first post i did'nt received a complete answer or you can say that my question was incomplete. i am new to this site so i was unable to access and didnt knew how to further question you on the same topic. if you can kindly give me the answer to the question below it would be a great help for me.

What is the usage of EDTA-Mg indicator for determination of Ca and Mg ions in Commercial milk powder?
Is it appropriate to use EDTA-Mg indicator for sample containing Mg ions in it (like Commercial milk powder)?
If yes, then will it (EDTA-Mg indicator) not interfere with the Mg ion concentration in the sample?
thank you
Title: Re: usage of EDTA-Mg indicator for determination of Ca and Mg ions in Commercial
Post by: nisha1 on July 17, 2009, 04:26:04 AM
Quote from: nisha1 on July 17, 2009, 02:53:37 AM
Quote from: nisha1 on July 17, 2009, 12:38:44 AM
Sir, actually i want to know the usage of EDTA-Mg indicator for determination of Ca and Mg ions in Commercial milk powder.
Is it appropriate to use Mg-EDTA indicator with the sample having Mg ions in it (like milk powder)?
If yes, then will it not interfere with the concentration of Mg ions already present in the sample?
sorry for the cross post but in my first post i did'nt received a complete answer or you can say that my question was incomplete. i am new to this site so i was unable to access and didnt knew how to further question you on the same topic. if you can kindly give me the answer to the question below it would be a great help for me.

What is the usage of EDTA-Mg indicator for determination of Ca and Mg ions in Commercial milk powder?
Is it appropriate to use EDTA-Mg indicator for sample containing Mg ions in it (like Commercial milk powder)?
If yes, then will it (EDTA-Mg indicator) not interfere with the Mg ion concentration in the sample?
thank you
sir, i have read the answer and i am also sure of it but according to this site- http://www.csudh.edu/oliver/che230/labmanual/calcium.htm   
i am getting confused. how much correct is the information provided in this. Please give a detailed explanation of it
Title: Re: Ca and Mg determination by EDTA method
Post by: Borek on July 17, 2009, 06:13:20 AM
I don't see what is confusing - they reiterate the same thing that is written on the titrations.info (http://www.titrations.info) site. You add MgEDTA2- complex to make it possible to use EBT as an indicator. Ading MgEDTA2- you add exactly the same amount of both Mg cation and ligand, so you don't interfere with the determination results. This is very basic stoichiometry.
Title: Re: Ca and Mg determination by EDTA method
Post by: nisha1 on July 17, 2009, 06:38:52 AM
thank you sir