Hello. This question is incomplete. The full question is:
"Consider the following reaction. 2NO(g) + 2H2(g) → N2(g) + 2H2O(g)
A proposed reaction mechanism is: NO(g) + NO(g) N2O2(g) fast N2O2(g) + H2(g) → N2O(g) + H2O(g) slow N2O(g) + H2(g) → N2(g) + H2O(g) fast
What is the rate expression? A. rate = k[H2] [NO]2 B. rate = k[N2O2] [H2] C. rate = k[NO]2 [H2]2 D. rate = k[NO]2 [N2O2]2 [H2]"
Answer:
A. rate = k[H2] [NO]2
Explanation:
A reaction mechanism is a term used to describe a set of phases that make up a chemical reaction. In these phases a detailed sequence of each step is shown, composed of several complementary reactions, which occur during a chemical reaction.
These mechanisms are directly related to chemical kinetics and allow changes in reaction rates to be observed in advance.
Reaction rate, on the other hand, refers to the speed at which chemical reactions occur.
Based on this, we can observe through the reaction mechanism shown in the question above, that the action "k [H2] [NO] 2" would have no changes in the reaction rate.
Answer : The internal energy change is, -506.3 kJ/mol
Explanation :
Formula used :
or,
where,
= change in enthalpy = 
= change in internal energy = ?
= change in moles
Change in moles = Number of moles of product side - Number of moles of reactant side
According to the reaction:
Change in moles = 0 - 2 = -2 mole
That means, value of 
= 0
R = gas constant = 8.314 J/mol.K
T = temperature = 
Now put all the given values in the above formula, we get
Therefore, the internal energy change is -506.3 kJ/mol
