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Chemistry Forums for Students => Undergraduate General Chemistry Forum => Topic started by: sriccomini on June 09, 2013, 02:35:54 PM

Title: Which cation will precipitate first/concentration when it does
Post by: sriccomini on June 09, 2013, 02:35:54 PM

Na2CO3 is added to a sol'n containing .02M BaCl2 and .003M CaCl2.
a) Which cation will precipitate first, Ba2+ or  Ca2+, as the concentration of Na2CO3 is increased?
b) Determine the concentration of CO3 2- at which precipitation begins. Given  Ksp (BaCO3) = 2.6E-9 and Ksp (CaCO3) = 5.0E-9

I know that if the cations are of equal concentration, a) can be determined simply from comparing Ksp values, but I'm unsure how to do this problem with different concentrations...

Title: Re: Which cation will precipitate first/concentration when it does
Post by: Borek on June 09, 2013, 04:38:38 PM

Do b first.