Hey there!:
More soluble in acidic solution than in neutral solution :
* Here the conjugate acids of AgCl , HgBr2 , and Pbl2 are HCl , HBr and HI which are strong , so these are slightly soluble in acidic solution .
* But the conjugate acid of BaCO3 is H2CO3 wich is weak acid, more soluble in acidic solution than in neutral solution.
Hope this helps!
