Can you help?

enter image source here

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"