I k cal is equal to
Correct answer: C. 4.18 x 10^3 J
- A. 41.8 x 10^3 J
- B. 418 x 10^3 J
- C. 4.18 x 10^3 J
- D. 0.418 x 10^3 J
Explanation
The correct conversion factor between calories and joules is 1 cal = 4.18 J. Therefore, 1 kilocalorie (kcal), which is equivalent to 1000 calories, converts to 4.18 x 103 J. Option C correctly applies this conversion factor. Options A and B overestimate the conversion by multiplying the factor by 10 and 100, respectively, while Option D underestimates it by dividing the factor by 10.
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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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