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๐ŸฅถEndothermic vs Exothermic๐Ÿ”ฅ

Reactions either take in or give out energy. The sign of the enthalpy change tells you which, and energy diagrams make it visual.

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๐ŸฅถEndothermic
  • โœ“Absorbs heat from the surroundings
  • โœ“Enthalpy change is positive
  • โœ“Products have more energy than reactants
  • โœ“Surroundings get colder
  • โœ“Examples: photosynthesis, ice melting
๐Ÿ”ฅExothermic
  • โœ“Releases heat to the surroundings
  • โœ“Enthalpy change is negative
  • โœ“Products have less energy than reactants
  • โœ“Surroundings get warmer
  • โœ“Examples: combustion, neutralization

Verdict

Endothermic reactions absorb energy and feel cold; exothermic reactions release energy and feel hot. The sign of ฮ”H tells you instantly which category applies.

Frequently asked

How does the sign of ฮ”H help?+

A positive ฮ”H means endothermic (heat absorbed); a negative ฮ”H means exothermic (heat released).

Why does an instant cold pack feel cold?+

It uses an endothermic dissolving process that absorbs heat from your skin.

Is combustion endo or exothermic?+

Combustion is strongly exothermic, releasing large amounts of heat and light.

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