Would be there any effect on an experiment ( Dissolving CaCl2 and Na2CO3 in distilled water to calculate the yield of calcium carbonate) if tap water containing calcium ions is used insted of deionized water to dissolve reactants ? Explain.
Recall that
Na2CO3 --> soluble
CaCO3 --> not soluble
if we try to find --> CaCO3 content
then we will have the next side reaction
when dissolving
Na2CO3 --> CO3-2 is present in solution
if the water has ions, since it is tap water, then Ca+2 is present
Ca+2 + CO3-2 = CaCO3(s) will precipitate
NOTE that this should not happen, since these cations of Calcium come from external source
therefore, the CaCO3 mass will be higher than it should be
the % CaCO3 increases, in sample, or overall yield, since CaCO3 increased (incorrectl)
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