Answer is: The sign of ΔHsys is - and the sign of qsurr is +.
First Law of Thermodynamics - any heat lost by the system must be absorbed by the surroundings.
-qsystem = qsurroundings.
There are two types of reaction:
1) exothermic reaction (chemical reaction that releases more energy than it absorbs).
For example, ΔH(reaction) = -225 kJ/mol; this is exothermic reaction.
2) endothermic reaction (chemical reaction that absorbs more energy than it releases).
Answer: The sign of [tex]\Delta H_{sys}[/tex] will be negative (-) and that of [tex]q_{surr}[/tex] will be positive (+).
Explanation: We are given a reaction of potassium hydroxide and water which is exothermic in nature.
Exothermic reactions are the reactions in which there is release of heat energy.
In these reactions, the energy of the products is lower than the energy of the reactants.
[tex]\Delta H=H_{products}-H_{reactants}[/tex]
Hence, energy change for the system will be negative (-ve).
'q' is the heat.
According to the convention,
q = +ve ; when heat is absorbed.
q = -ve ; when heat is released.
As the heat is transferring from system to surrounding, so the heat is absorbed by the surrounding. Hence, the sign of 'q' will be positive (+ve)
