Concept explainers
Interpretation:
Empirical formula and standard enthalpy of formation of a hydrocarbon is to be determined.
Concept introduction:
Empirical formula of a chemical compound is the simplest ratio of atoms present in it.
Molecular formula is whole number multiple of the empirical form given by the expression as follows:
Here, n is the whole number multiple.
The number of moles of a compound is determined as follows:
Answer to Problem 102AP
Solution:
(a)
Empirical formula of the compound is
(b)
Enthalpy of formation of the hydrocarbon is
Explanation of Solution
Given information: Combustion of
a)
For determining the empirical formula of a compound, the number of moles of the product is determined by the expression as follows:
The number of moles of
Substitute
The number of moles of
Substitute
Therefore, molar ratio is calculated as follows:
Hence, the empirical formula is
Given information: The molecular mass of the hydrocarbon is
b)
Molecular mass of lysine
The empirical formula mass is calculated as follows:
Now, whole number multiple
Molecular formula is as follows:
Therefore, molecular formula of the hydrocarbon is
Equation for combustion of the hydrocarbon is represented below.
Energy produced by
Mass of
Energy produced by
Also, total enthalpy of the reaction is given by the equation as follows:
Substitute
Therefore,
Hence, the standard enthalpy of the formation of
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Chapter 5 Solutions
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