First law of thermodynamics is mathematically represented as:
Correct answer: C. ΔE = q - w
- A. ΔE = E2 - E1
- B. ΔE = PDV
- C. ΔE = q - w
- D. None of the above
Explanation
The first law of thermodynamics is a statement of energy conservation, expressed as ΔE = q - w, where ΔE is the change in internal energy of a system, q is the heat added to the system, and w is the work done by the system. Option A simply represents a change in internal energy without considering heat or work. Option B describes a specific scenario of work done but does not encompass the full first law. Option D is incorrect because there is a correct answer provided, which is option C.
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About Thermochemistry and Energetics of Chemical Reactions
Thermochemistry measures energy changes in chemical reactions and distinguishes exothermic from endothermic processes. Work covers systems, surroundings and state functions, internal energy, the first law of thermodynamics, enthalpy and Hess's law, including the sign conventions used when heat enters or leaves a system.
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