Answer:
Because the value of K is huge.
Explanation:
The tautomer is a kind of isomer in which exist an equilibrium between a ketone and an enol, or between an aldehyde and an enol. So, in the enolization, the ketone is the reactant and the enol is the product.
The equilibrium reaction can be characterized by an equilibrium constant, which is the ratio of the concentration of the products by the concentration of the reactants.
Because the constant K is extremely large (10¹³) we can conclude that the concentration of the product will be greater than the concentration of the reactant, in the equilibrium. It means that the concentration of the enol will be greater.
So, the ketone is unstable and forms in a great amount the more stable product, the enol.
Molecular weight it stands for molecular weight
The answer is A, biogeochemical cycles.
Answer : The fuel value and the fuel density of pentane is, 49.09 kJ/g and
respectively.
Explanation :
Fuel value : It is defined as the amount of energy released from the combustion of hydrocarbon fuels. The fuel value always in positive and in kilojoule per gram (kJ/g).
As we are given that:

Fuel value = 
Molar mass of pentane = 72 g/mol
Fuel value = 
Fuel value = 49.09 kJ/g
Now we have to calculate the fuel density of pentane.
Fuel density = Fuel value × Density
Fuel density = (49.09 kJ/g) × (0.626g/mL)
Fuel density = 30.73 kJ/mL = 
Thus, the fuel density of pentane is 
The smaller number is the number of protons, and the greater number is the mass.