Calculate

(a) The molality of KOH in a solution prepared from 3.12 g of KOH and 67.0 g of water;

(b) The mass (in grams) of ethylene glycol, HOC₂H₄OH, that should be added to 0.74 kg of water to prepare 0.28 m HOC₂H₄OH(aq);

(c) The molality of an aqueous 3.68% by mass HCl solution.