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 $$225 \mathrm{~u}$$ ?
Calculate $$\Delta \mathrm{S}_{\text {total }}$$ for the following reaction at $$300 \mathrm{~K}$$.
$$\mathrm{NH}_4 \mathrm{NO}_{3(\mathrm{~s})} \longrightarrow \mathrm{NH}_{(\mathrm{aq})}^{+}+\mathrm{NO}_{3(\mathrm{aq})}^{-}$$
$$\left(\Delta \mathrm{H}=28.1 \mathrm{~kJ} \mathrm{~mol}^{-1}, \Delta \mathrm{S}_{\mathrm{sys}}=108.7 \mathrm{~J} \mathrm{~K}^{-1} \mathrm{~mol}^{-1}\right)$$