In the following questions, a statement of Assertion (A) followed by ...
Reason (R) : Combustion reactions breaks the bonds of organic compound molecules, and the resulting water and carbon dioxide bonds always release more energy than was used to break them originally. That’s why burning organic compounds produces energy and is exothermic.
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In the following questions, a statement of Assertion (A) followed by ...
Assertion (A): Combustion of all organic compounds is an exothermic reaction.
Reason (R): The enthalpies of all elements in their standard state are zero.
Explanation:
The given assertion states that the combustion of all organic compounds is an exothermic reaction. In order to understand this assertion, we need to first clarify the concept of combustion and exothermic reactions.
Combustion:
Combustion is a chemical reaction in which a substance reacts with oxygen to produce heat and light. It is a type of oxidation reaction that is usually accompanied by the production of a flame.
Exothermic Reactions:
Exothermic reactions are chemical reactions that release energy in the form of heat. In these reactions, the products have lower energy than the reactants, resulting in a release of energy to the surroundings.
Now, let's analyze the reason given in the statement.
The reason states that the enthalpies of all elements in their standard state are zero. Enthalpy is a thermodynamic property that represents the heat content of a system. The standard state of an element is its most stable form at a pressure of 1 bar and a temperature of 298 K.
Analysis of the Reason:
The reason given in the statement is not directly related to the assertion. The enthalpies of elements in their standard state being zero does not necessarily imply that the combustion of organic compounds is exothermic.
Conclusion:
From the analysis above, we can conclude that both the assertion and the reason are true, but the reason does not provide a correct explanation for the assertion. Therefore, the correct option is (B) – Both A and R are true, but R is not the correct explanation of A.
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