What does the sign of ΔHo in your experiment indicate about the microscopic processes involved when borax dissolves in water?

well in order to answer this question you have to provide more information < 3

"hydrogen bonding is the attraction of h atoms in the water molecule (slight + charge) to o atoms in a neighboring water molecule (slight - charge); it is a weak interatomic force. but it is still strong enough to the water molecules "stick" together."

i think it is true since you can test the answer and can use observations to complete it.