Looking at both reactions, we can see that the combustion of carbon, graphite or diamond, leads to the formation of carbon dioxide and energy. Since energy is a product of the reaction, we known that this is an exothermic reaction. The value of the change in enthalpy, ΔH, will be negative.
A negative value of ΔH in each exothermic reaction suggests that the carbon dioxide product is at a lower energy than the reactants. And since more energy is released in the combustion of diamond compared to graphite, we know that diamond has a higher internal energy than graphite.
we find the number of moles with the formula
pV=nRT
27C=300k
3.2*30=n*0.082*300
n=96/24.6=3.9 moles
we have the mass ant the number of moles so we can calculate the molar mass
283.3/3.9=72.64g/moles
that means X's mass is 72.64/2=36.3 so the element is Kr(Kriptonium)
Explanation:
It is known that molarity is the number of moles present in a liter of solution.
Mathematically, Molarity = 
Hence, calculate the molarity of given solution as follows.
Molarity of citric acid = 
= 
= 0.173 M
As citric acid is a triprotic acid so, upon dissociation it gives three hydrogen ions.
Normality = Molarity × no. of hydrogen or hydroxide ions
= 0.173 × 3
= 0.519 N
Thus, we can conclude that molarity of given solution is 0.173 and its normality is 0.519 N.