Answer:
500ml water
Explanation:
Molarity x Volume in liters (concentrated soln) = Molarity x Volume (diluted soln) ∴
250ml X 12M HCl = 4M x Volume of diluted solution
=> Volume of diluted solution = (250ml)(12M)/(4m) = 750 ml final solution vol. after mixing.
So the amount of water added to the 250ml of 12M acid = 750ml - 250ml = 500ml of water.
