Hydrogen reacts with oxygen based on the following equation:
2 H2<span> + O</span>2<span> → 2 H</span>2<span>O
</span>
From the periodic table:
molar mass of hydrogen = 1 gram
molar mass of oxygen = 16 grams
From the balanced equation above, we can find that:
4 grams of hydrogen react with 32 grams of oxygen to produce 36 grams of water.
This means that: 0.73 grams of hydrogen require (0.73x32) / 4 = 5.84 grams of oxygen to react with.
Since only 3.28 grams of oxygen are reacting, this means that oxygen is our limiting reagent and that the reaction would stop once the amount of oxygen is consumed.
So, we will base our calculations on oxygen.
mass of water produced from 3.28 grams of oxygen can be calculated as follows:
mass of water = (3.28 x 36) / 32 = 3.69 grams
Explanation:
The given data is as follows.
, 
= 2257 kJ/kg, 
= ?
For water, 
= 4.184 
Formula to calculate heat of vaporization is as follows.
= 
Hence, putting the values into the above formula as follows.
=
= 
= 2257 kJ/kg - 376.56 kJ/kg
= 1880.44 kJ/kg
Thus, we can conclude that enthalpy of liquid water at 
is 1880.44 kJ/kg.
