What volume of 0.140 M HCl is needed to neutralize 2.53g of Mg(OH)_2

Answer 1

Mg(OH)2 + 2HCl ==> 2H2O + MgCl2
mols Mg(OH)2 = grams/molar mass
Convert mols Mg(OH)2 to mols HCl using the coefficients in the balanced equation. That's mols HCl = 2x mols Mg(OH)2.

Then M HCl = mols HCl/L HCl. You know mols HCl and M HCl, substitute and solve for L HCl.