Identifying Endothermic and Exothermic Reaction

Instant cold packs use chemical reaction. Are these reactions endothermic or exothermic?

• • Endothermic – takes heat from surroundings
  • Exothermic – gives  heat to surroundings
  • Cold pack – feel cold, lower temperature then normal surroundings, absorbs heat energy
    • Heat flows from hot to cold → cold pack takes heat

Cold packs are endothermic because they take heat from their surroundings.