(a)
Interpretation:
The merits of the calculation data has to be discussed.
Concept introduction:
Combustion reaction:
Combustion is an exothermic reaction between a fuel (the reductant) and an oxidant. Oxidant is usually atmospheric oxygen. Generally organic molecule undergoes combustion reaction which produces carbon dioxide and water molecule.
(a)
Explanation of Solution
Generally, the number of carbon atoms is more (number of atoms is more), obviously it has higher molar masses in the fuels therefore it release more energy when burned.
Therefore, the number of atoms in octane is more so, it has more
The comparison of the molar heats of combustion of the molecule is based on the same amount of each substance and heat released per gram of each fuel.
Both the values are closer. It is not possible to found with just two data points.
Though, butane has less number of hydrocarbons than octane and it releases slightly more heat per gram than the octane.
Therefore, the result clearly tells that the heat comparisons should be based on the same mass of fuel.
(b)
Interpretation:
The heat of combustion per gram of candle wax (
Concept introduction:
Combustion reaction:
Combustion is an exothermic reaction between a fuel (the reductant) and an oxidant. Oxidant is usually atmospheric oxygen. Generally organic molecule undergoes combustion reaction which produces carbon dioxide and water molecule.
(b)
Explanation of Solution
Generally, the number of carbon atoms is more (number of atoms is more), obviously it has higher molar masses in the fuels therefore it release more energy when burned.
Therefore, the number of atoms in octane is more so, it has more chemical bonds, hence It has a larger heat of combustion than butane.
The comparison of the molar heats of combustion of the molecule is based on the same amount of each substance and heat released per gram of each fuel.
Both the values are closer. It is not possible to found with just two data points.
Though, butane has less number of hydrocarbons than octane and it releases slightly more heat per gram than the octane.
Therefore, the result clearly tells that the heat comparisons should be based on the same mass of fuel.
The number of atoms is more in Candle wax, it has high molar mass. When comparing the above data values, we can predict the heat of combustion per gram is expected to be slightly smaller and the heat of combustion per mole is expected to be larger than octane.
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Chapter 5 Solutions
CHEMISTRY IN CONTEXT (LL)
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