Calculate ΔE: Endo- or Exothermic? Solving Problems with ΔE Equation

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SUMMARY

This discussion focuses on calculating the change in energy (ΔE) for various thermodynamic processes and determining whether they are endothermic or exothermic. The ΔE equation is clarified as ΔE = q + w, where q represents heat absorbed or released and w represents work done by or on the system. Three specific cases are analyzed: (A) a system absorbing 105 kJ of heat while doing 29 kJ of work, (B) a system with q = 1.50 kJ and w = -657 J, and (C) a system releasing 57.5 kJ of heat while doing 22.5 kJ of work. The key conclusion is that a system is exothermic if it releases more energy than it absorbs, and endothermic if it absorbs more energy than it releases.

PREREQUISITES
  • Understanding of thermodynamic principles, specifically the concepts of heat (q) and work (w).
  • Familiarity with the first law of thermodynamics and energy conservation.
  • Basic knowledge of exothermic and endothermic processes.
  • Ability to perform unit conversions, particularly between kJ and J.
NEXT STEPS
  • Study the first law of thermodynamics in detail.
  • Learn how to apply the ΔE equation in various thermodynamic scenarios.
  • Explore examples of endothermic and exothermic reactions in chemistry.
  • Investigate the implications of energy changes in physical and chemical processes.
USEFUL FOR

Chemistry students, thermodynamics enthusiasts, and professionals in fields related to energy management and chemical engineering will benefit from this discussion.

bigzabuda
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The problems asks,
Calculate ΔE, and determine whether the process is endothermic or exothermic for the following cases:(A) A system absorbs 105 kJ of heat from its surroundings while doing 29 Kj of work on the surrounding;(B) q = 1.50 kJ and w = -657j; (C) the system releases 57.5 kJ of heat while doing 22.5 kJ of work on the surrounding.

I am confused with the question, I am pretty sure the equation is ΔE = q+pΔv

im not sure what to do can anyone help me, thanks.
 
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It is easier than that.
You have two values:
- Absorbed heat. It is an amount of energy which goes into the system
- Work done by the system. It is an amount of energy which goes out of the system.

Now a system is exothermic if it releases more energy than it absorbs, and endothermic if the other way around.
 

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