The latent heat is correlated with energy as follows:
Q = mL
550 * 103 = 14 * 103 * L
L = 39.285 J /g
Thus, latent heat of the substance is 39.285 j /g
The given question is incomplete. The complete question is:
The combustion of propane (C3H8) in the presence of excess oxygen yields
and
When only 2.5 mol of
are consumed in order to complete the reaction, ________ mol of
are produced.
Answer: Thus when 2.5 mol of
are consumed in their reaction, 1.5 mol of
are produced
Explanation:
The balanced chemical equation is:

According to stoichiometry :
5 moles of
produce = 3 moles of 
Thus 2.5 moles of
will produce =
moles of 
Thus when 2.5 mol of
are consumed in their reaction, 1.5 mol of
are produced
My view point is that i disagree and that the rules are completely different
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