Molarity (M) = moles of solute (mol) / Volume of the solution (L)
Molarity of the given solution = 6.00 M
Volume taken to prepare 2.00 M = 175 mL
moles in 175 mL = 6.00 M x 0.175 L
= 1.05 mol
Hence, moles of HCl in 2.00 M solution = 1.05 mol
By applying formula,
2.00 M = 1.05 mol / Volume
Volume = 0.525 L
Hence, volume needed to prepare the solution = 0.525 L
Volume of 6.00 M solution + volume of water = 0.525 L
Hence, the volume of water needed to add = 0.525 L - 0.175 mL
= 0.350 L = 350 mL
