What is the mole fraction of solute in 2.5 molal aqueous solution?

2.5 molal solution means 2.5 mole of solute are present in 1000 g of water.

Moles of water = \(\frac{1000}{18}\) = 55.56

Mole fraction of solute = \(\frac{2.5}{2.5+55.56}\) = 0.043