Answer:
The forward reaction is an exothermic reaction.
Explanation:
An exothermic reaction is one in which energy is released, usually in the form of heat hence the enthalpy of the reaction is negative. When a reaction exothermic, the energy of the reactants is greater than the energy of the products hence the excess energy is given out as heat. The reactants lie at a higher energy level in the reaction profile compared to the products.
When we look at the reaction given in the question, NO(g) ⇌ 12N2(g) + 12O2(g) ΔH = −90.3 kJ , we can easily see from the thermochemical reaction that the forward reaction is exothermic, energy is released by the reaction system as evidenced by the negative enthalpy of reaction.
All. It depends on the lab setup, equipment, and expertise.
Given that,
Work done by the system = 125 J
Energy released when it cools down = 438 J
To find,
The change in internal energy.
Solution,
As heat is released by the system, Q = -438 J
Work done by the system, W = -125 J
Using the first law of thermodynamics. The change in internal energy is given by :

So, the change in internal energy is 563 J.
Democritus because of Greek atomism. In the 5th century BCE, Leucippus and his pupil Democritus proposed that all matter was composed of small indivisible particles called atoms.