An aqueous solution containing MgCl2 and HCl was analyzed by first titrating a 25.00 ml aliquot to a bromocresol green end point with 18.96 ml of 0.02762 M NaOH. A 10.00 ml aliquot was then diluted to 50.00 ml with distilled water and passed through a strong-acid ion-exchange resin. The eluate and washings required 36.54 ml of the NaOH solution to reach the same end point. Report the molar concentrations of HCl and MgCl2 in the sample.