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1 Answer
Apr 2, 2018

#"700 mL"#

Explanation:

Molarity #("M")# is given as

#"M" = "n"/"V"#

where

  • #"n ="# Number of moles of solute
  • #"V ="# Volume of solution in litres

#"n = MV"#

According to the hint mentioned, #"n = constant"#

So,

#"M"_1"V"_1 = "M"_2"V"_2#

#"V"_2 = ("M"_1"V"_1)/"M"_2 = (3 cancel"M" × "50 mL")/(0.2 cancel"M") = "750 mL"#

Volume of water to be added #"= 750 mL - 50 mL = 700 mL"#