Answer:
Besides electrical, chemical, and thermal energy, some other forms of energy include mechanical and sound energy. Any of these forms of energy can change into any other form. Often, one form of energy changes into two or more different forms.
Your answer is

but if you are looking for some explanation check description below :)
Diphosphorus trioxide formula is:

Di stands from 2 atoms of something, in this case we have 2 atoms of Phosphorus.
Trioxide means that we have 3 atoms of oxygen in this substance that's why we have:

And water is just

Unbalanced formula is:

Now we need to balance this equation
On left hand side we have 2 atoms of Phosphorus, on right hand side we have just one atom of Phosphorus, that's why we need to put 2 before

Now we need to count all atoms of oxygen and hydrogen and make it equal on both side.
So we need to put 3 on left hand side before water to make this equation balanced.
That's why correct answer is:
Ethane can be turned into its carboxylic acid form called the ethanoic acid by a series of steps. First chlirinate it in the presence of light. Then, add potassium hydroxide to get an alcohol. Finally, adding KMnO4 to oxidize it to a carboxylic acid. The equations are as follows:
C2H6 + Cl2 ---> C2H5Cl + HCl
C2H5Cl+KOH-> C2H5OH+ KCl.
C2H5OH ----KMnO4 ---> CH3COOH.
Explanation:
this is the one i found.....