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.
what is a fire piston?
*a tool for starting a fire, likely invented in Ancient Southeast Asia.*
dont know the second one lol.
Answer:
The temperatures of the objects must be different
Explanation:
if heat is flowing between two objects, then the objects must be at different temperatures.
-19.15 degrees Celsius. 254k-273.15=-19.15
You have to subtract 273