The balanced chemical reaction is written as:
MnCl2(s)+H2SO4(aq)→MnSO4(aq)+2HCl(g)
We are given the amount of hydrochloric acid to be produced in the reaction. This value will be the starting point for the calculations.We do as follows:
.0525 L HCl ( 1 mol / 22.4 L ) ( 1 mol MnCl2 / 2 mol HCl ) (125.84 g / 1 mol ) = 0.15 g MnCl2