Magnesium oxide is not very soluble in water, and is is difficult to titrate directly. It's purity can be determined by use of a back-titration method. 4.06 g of impure magnesium oxide was completely dissolved in an excess of 0.20 mol/L for neutralization. Calculate the mass of magnesium oxide that reacted with the initial hydrochloric acid, hence the % purity of magnesium oxide.

2 answers

Please help with a good procedure. Thanks.
You've left out part of the problem. How much of the 0.20 M acid( what acid or at least is it monoprotic or diprotic). Then you don't give any numbers for the back titration. Look over your post and fill in the blanks.