Question

What is the molar solubility of magnesium carbonate (MgCO₃) in water and in 0.01 M Na₂CO₃? Explain how the solubility of MgCO₃ changes using Le Chatelier’s Principle. The solubility-product constant for MgCO₃ is 3.5x10^-8 at 25°.

Answer 1

Nazco2 fully dissodates in aqueous solution 2- Nazcos Cay) 2 Nat +Co3 Ca9) (aa) from the reaction stoichiometry we can say that 0.01 mole Nazc03 gives 0.01 mole co2 solution in aqueous Now tets solubility of Mgco x mote lL Cx M) Mg cos dissoiates as 2 2t Caq) +L0 Caq) Mg coz lag) mote co Here mofe Mgco3 gives Hence, total concenration of co (0.01+ M and CMg 2 M. KSP xC0.01+) 3.5 X10 O.01 x t 3.5x 108 0.01 -3.5XIO& O.

sing Sreedhar - Achaya's fohmula, we get- - 0.01t(o.01) 4x Ix3.5X10 2X1 0.01 t 0.010007 2 NOW 0.01- 0010007 2. ODI can not be negative an repvesents The value ot wnentration [oncenhation can't ke negative Solh 2 -0.01+ 0. 010007 2 3.5 X10 tHenee solubiuty of g mote 3.5X10 9 3.5 X106 M Acording to Le chatelier's phineiple 1f we add produts re uere cog the equu librium wrl shift towards reautant hde henue soluubility decreases. i.e- wore the Nario will be added lees soluble will be the g co3