posted by christa .
How many mL of 0.416 M of HCl are needed to dissolve 8.68 g of BaCO3?
BaCO3 + 2HCl ==> H2O + CO2 + BaCl2
mols CaCO3 = grams/molar mass = ?
mols HCl = 2x that. (Look at the coefficients in the balanced equation.)
M HCl = mols HCl/L HCl You have mols and M, solve for L HCl and convert to mL.