Which from following sentences is NOT correct?

A solution of nonvolatile solute is obtained by dissolving $$1.5 \mathrm{~g}$$ in $$30 \mathrm{~g}$$ solvent has boiling point elevation $$0.65 \mathrm{~K}$$. Calculate the molal elevation constant if molar mass of solute is $$150 \mathrm{~g} \mathrm{~mol}^{-1}$$.

A weak base is $$1.42 \%$$ dissociated in its $$0.05 \mathrm{~M}$$ solution. Calculate its dissociation constant.

What is the value of percent atom economy when an organic compound of formula weight $$75 \mathrm{~u}$$ is obtained from reactants having sum formula weight $$225 \mathrm{~u}$$ ?