Enthalpy Changes in Solution (OCR A-Level Chemistry A): Flashcards
📚Flashcards
Practise the cards
10 cards from this deck
ShowHide
Practise the cards
10 cards from this deck
Def:
Def:
Enthalpy change when 1 mol solute dissolves completely
Def:
Def:
Enthalpy change: gaseous ions to 1 mol aqueous ions
Two stages of ionic compound dissolving
Two stages of ionic compound dissolving
Lattice breaks to gaseous ions; ions hydrate
Breaking ionic lattice: endo or exothermic?
Breaking ionic lattice: endo or exothermic?
Endothermic (energy needed to overcome attractions)
Hydration of ions: endo or exothermic?
Hydration of ions: endo or exothermic?
Exothermic (always releases energy)
Hess's law for dissolution (components)
Hess's law for dissolution (components)
Lattice + solution enthalpy = sum of hydration enthalpies
Formula for energy change in solution
Formula for energy change in solution
in represents
in represents
Mass of solution (water + dissolved compound)
Temp decreases: sign?
Temp decreases: sign?
Positive (endothermic)
Cold pack mechanism
Cold pack mechanism
Endothermic dissolution absorbs heat from surroundings