Answer: b.
is positive and
is positive.
Explanation:-
As the temperature of the pack drops, the energy has been absorbed from the pack for dissolution of
in water. Thus as the energy has been absorbed in the reaction, the reaction is endothermic and the change in enthalpy i.e.
is positive.
The entropy is the measure of degree of randomness. The entropy increases when the randomness increases and the entropy decreases when the randomness decreases. When a substance dissolves in water, it dissociate into ions and hence the randomness increases thus the change in entropy i.e.
is positive.
2) mg donates two protons to O.
A catalyst will speed up the activation energy and therefore speed up the reaction. The products will form fast because of this.
B
. They are large and occur at shallow depths near the where the plates diverge.