Answer:

Explanation:
N2(g)+O2(g)⇌2NO(g), 
N2(g)+2H2(g)⇌N2H4(g), 
2H2O(g)⇌2H2(g)+O2(g), 
If we add above reaction we will get:
2N2(g)+2H2O(g)⇌2NO(g)+N2H4(g) Eq (1)
Equilibrium constant for Eq (1) is 
Divide Eq (1) by 2, it will become:
N2(g)+H2O(g)⇌NO(g)+1/2N2H4(g) Eq (2)
Equilibrium constant for Eq (2) is 

Answer:
When the water is mixed with water at lower temperature the effective temperature of the system (i.e the water at lower temperature) will increase, thereby increasing it's entropy
Explanation:
The answer that "the entropy will is increases" is correct as:
The water at 90° C i.e at higher temperature is mixed with the water at 10° C i.e the water at the lower temperature.
The water at lower temperature will have molecules with lower energy while the water with higher temperature will have molecules undergoing high thermal collisions. Thereby, when the water is mixed with water at lower temperature the effective temperature of the system (i.e the water at lower temperature) will increase, thereby increasing it's entropy.
Therefore, the answer is correct with respect to the water at lower temperature.
Meanwhile, for the water at higher temperature , the temperature of the system will decrease. Thus, the entropy of the water at higher level will decrease.
Answer: Heat of the solution = mass water × specific heat water × change in temperature
mass water = 260ml (1.00g/ml ) = 260g
specific heat of water = c(water) = 4.184J/ g°C
Heat change of water = final temperature - initial temperature
= 26.5 - 21.2
= 5.3 °C
H = 260 g ( 4.184J/g°C ) (5.3°C) = 5765J
Molar heat = 
= 16473J/mol
Explanation: finding molar heat requires first to look at specific heat of water and the change of water temperature