The chemical formula of water is written as H2O we can just use the ratio of the atoms since we are not given the reaction. Hydrogen is a diatomic substance so that it exists as H2. We calculate as follows:
0.253 mol H2O ( 1 mol H2 / 1 mol H2O ) = 0.253 H2 needed
Hope this answers the question. Have a nice day.
The liquid phase occurs in between
That would be a depression..
Answer:
A) 
Explanation:
m = Mass of water = 38.9
M = Molar mass of water = 18 g/mol
= Avogadro's number = 
The reaction of electrolysis would be

Number of moles of 

From the reaction it can be seen that 2 moles of
gives 1 mole of 
So, number of moles of
produced is

Number of molecules

So,
of oxygen is produced.
Iodine and Calcium is the correct answer