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Chemistry Forums for Students => Inorganic Chemistry Forum => Topic started by: kumarentran on May 22, 2004, 12:15:42 AM

Title: I need help on CuCO3 dissolution?
Post by: kumarentran on May 22, 2004, 12:15:42 AM
i have to synthesis Cu(II)4-halobenzoate.
the reagents are 4-halo benzoic acid and CuCO3(coppercarbonate).
but the CuCO3 doesnt seem to dissolve in order for the Cu2+ ions to form a dimer complex.
the product wanted is Cu2.(4-halobenzoate)4.
And the benzoic acid keeps forming again when the stirring stops.
Please give me a way( procedure, solvent, catalyzer ) to dissolve the CuCO3 and make the reaction Happen.
mail me.
kumarentran@hotmail.com
URGENT!!!!!!!!!!!!!!!!!!!!
Title: Re:I need help on CuCO3 dissolution?
Post by: Donaldson Tan on May 22, 2004, 01:24:26 AM
Must u use the water-insoluble Copper(II) Carbonate? Aq. Cu(NO3)2 can be source for aq. Cu2+ ions too.
Title: Re:I need help on CuCO3 dissolution?
Post by: AWK on May 22, 2004, 04:39:20 AM
Benzoic acids are stronger than carbonic acid, so reaction should take place. However, both copper carbonate and copper benzoate are insoluble in water and organic solvents and both show almost the same color. And this is the main problem. Moreover, this reaction is heterogenous and must proceed slowly.

The better solution of the problem is to dissolve copper carbonate in hydrochloric or sulfuric acid (or use of soluble copper salt) and use of sodium benzoate instead of benzoic acid itself.