What is the mass of a mole of water containing 50% of heavy water `(D_(2)O)`?

Answer

19

Explanation

As water contains 50% `D_(2)O`, this means that it contains
`1/2` mole of `H_(2)O` and `1/2` mole of `D_(2)O`. Mass of `1/2` mole of `H_(2)O = 1/2 xx 18 = 9g`. Mass of `1/2` mole of `D_(2)O = 1/2 xx (2 xx 2 + 16) =10 g`. Hence, molar mass of the given sample of water `= 9 +10 = 19 g "mol"^(-1)`