How many milliliters of 1.60 M HCl must be added to 25.0 mL of 1.60 M Ca(OH)2 to make a neutral solution

Best answer gets 20 points.

Ma Va ia = Mb Vb ib

Where:
M is molarity
V is volume
i is the van 't Hoff factor (integer number of moles of ion in solution per mole of acid/base; ratio of stoichiometric coefficients)
subscript 'a' denotes acid
subscript 'b' denotes base

(1.60 M) [Va] (1) = (1.60 M) (0.025 L) (2)

Va = (0.025 L) (2) / (1)

Va = 0.050 L

Note: Since this is just a ratio/proportion, you could use mL as your unit of volume.

50.0 milliliters of 1.60 M HCl must be added to 25.0 mL of 1.60 M Ca(OH)2 to make a neutral solution as 2 HCl + Ca(OH)2 = CaCl2 + 2H2O