If the internal energy of a thermodynamic system is increased by 300j while 75j of expansion work is done?
how much heat was transferred and in which direction to or from the system?

The internal energy of the system is characterized by the equation U = Q + W where U is the internal energy, Q is the heat and W is work. You are given 300J of internal energy and 75J of expansion work. The heat energy is 225J.

water and alcohols have similar properties because water molecules contain hydroxyl groups that can form hydrogen bonds with other water molecules and with alcohol molecules, and likewise alcohol molecules can form hydrogen bonds with other alcohol molecules as well as with water.