Answer: Would be D. Fe and S have an ionic bond, while S and O have covalent.
Hope that helps.
Answer : The correct expression will be:

Explanation :
The chemical reactions are :
(1)

(2)

The final chemical reaction is :

Now we have to calculate the value of
for the final reaction.
Now equation 1 is multiply by 2 and then add both the reaction we get the value of 'K'.
If the equation is multiplied by a factor of '2', the equilibrium constant will be the square of the equilibrium constant of initial reaction.
If the two equations are added then equilibrium constant will be multiplied.
Thus, the value of 'K' will be:

I think it’s b but I could be wrong
It’s a or b i think it’s b
<span>To raise the liquid temperature to the point of boiling take 1231.776 joules of energy. To convert to a gas takes 5320.645 joules. To raise to 108 degrees Celsius takes 1456.848 joules. Total amount of energy needed (as heat) equals 8009.269 joules or 8.009 kj.</span>