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A: Total enthalpy change of a multistep ...

A: Total enthalpy change of a multistep process is sum of ` Delta H_(1) + Delta H_(2) + Delta H_(3) + ....`
R: When heat is absorbed by the system, the sign of q is taken to be negative.

A

If both Assertion & Reason are true and the reason is the correct explanation of the assertion , then mark (1)

B

If both Assertion & Reason are true and the reason is not the correct explanation of the assertion, then mark (2)

C

If Assertion is true statement but Reason is false, then mark (3)

D

If both Assertion is true statement but Reason is false, then mark (3)

Text Solution

AI Generated Solution

The correct Answer is:
To solve the question, we need to analyze the statements provided: **Statement A:** The total enthalpy change of a multistep process is the sum of ΔH₁ + ΔH₂ + ΔH₃ + ... **Statement R:** When heat is absorbed by the system, the sign of q is taken to be negative. ### Step-by-Step Solution: 1. **Understanding Statement A:** - According to Hess's Law, the total enthalpy change for a chemical reaction is the sum of the enthalpy changes for each step of the reaction, regardless of the pathway taken. - Therefore, if a reaction occurs in multiple steps, the total enthalpy change (ΔH_total) can indeed be expressed as ΔH₁ + ΔH₂ + ΔH₃ + ..., which confirms that Statement A is true. 2. **Understanding Statement R:** - The sign convention for heat (q) is crucial in thermodynamics. When a system absorbs heat, this is considered an endothermic process, and the heat absorbed is assigned a positive value (q > 0). - Conversely, when the system releases heat, it is an exothermic process, and the heat released is assigned a negative value (q < 0). - Therefore, the statement "When heat is absorbed by the system, the sign of q is taken to be negative" is incorrect. Instead, it should be stated that when heat is absorbed, the sign of q is positive. 3. **Conclusion:** - Statement A is true, while Statement R is false. Thus, the correct answer to the question is that A is true and R is false. ### Final Answer: - Statement A is True. - Statement R is False.
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