Answer:
The answer is explained below:
Explanation:
Given the chemical equation:
N2H4(g)+H2(g)→2NH3(g)
The standard enthalpy of formation is given by the following formula:
ΔH^0 rxn = ∑ B reactants - ∑ product
-187.78 kJ/mol = [( 1x B N-N) + (1 x B N-H ) + (1 x b H-H)] - [ 6 x B N-H]
-187.78 kJ/mol = [( 1x B N-N) +(4 x 391 kJ/mol) + (1 x 436 kJ/mol)] - [ 6x 391 kJ/mol ]
-187.78 kJ/mol = B N-N + (1564 + 436 - 2346) kJ/mol
B = 158.22 kJ/mol
So, in this case the enthalpy of N-N bond is 158 kJ/mol
Answer : The pH will be, 3.2
Explanation :
As we known that the value of solubility constant of ferric hydroxide at 
is, 
Amount or solubility of iron consumed = (1.800 - 0.3) mg/L = 1.5 mg/L
The given solubility of iron convert from mg/L to mol/L.
The chemical reaction will be:
The expression of solubility constant will be:
![K_{sp}=[Fe^{3+}]\times [3OH^-]^3](https://tex.z-dn.net/?f=K_%7Bsp%7D%3D%5BFe%5E%7B3%2B%7D%5D%5Ctimes%20%5B3OH%5E-%5D%5E3)
Now put all the given values in this expression, we get the concentration of hydroxide ion.
![2.79\times 10^{-39}=(2.7\times 10^{-7})\times [3OH^-]^3](https://tex.z-dn.net/?f=2.79%5Ctimes%2010%5E%7B-39%7D%3D%282.7%5Ctimes%2010%5E%7B-7%7D%29%5Ctimes%20%5B3OH%5E-%5D%5E3)
![[OH^-]=1.5\times 10^{-11}M](https://tex.z-dn.net/?f=%5BOH%5E-%5D%3D1.5%5Ctimes%2010%5E%7B-11%7DM)
Now we have to calculate the pOH.
![pOH=-\log [OH^-]](https://tex.z-dn.net/?f=pOH%3D-%5Clog%20%5BOH%5E-%5D)
Now we have to calculate the pH.
Therefore, the pH will be, 3.2
The taste of Acid is Sour, that of Base is Bitter and salt is salty. So, Pickle and Lemons give sour taste due to presence of Acids. The sour taste of Lemon is due to presence of Citric Acid in it. While the sour taste of Pickle is due to presence of Vinegar (5% Acetic Acid Solution). Vinegar is mainly used to prevent the Pickle from Bacterial Attack.
Assuming that none of the liquid evaporates, the mass of the ice would be the same as the mass of the water because no chemical change occurred, only a phase change occurred.
Hope this helps
