If 0.360 g of an unknown triprotic acid (H3X) requires 27.00 mL of a 0.500 M NaOH solution for neutralization, what is the molecular weight of the

If 0.360 g of an unknown triprotic acid (H3X) requires 27.00 mL of a 0.500 M NaOH solution for neutralization, what is the molecular weight of the acid? If it is a common phosphorous containing oxy-acida, what is the formula and name?