P. 264 P Chemical Reactions/ Equations

Neutralization Reaction Reaction between and acid and a base Products are salt and water. Ex- HCl + NaOH  NaCl HCl + KOH  H2O + KCl HNO3 + NaOH  H2O + NaNO3 

Chemical reaction/equation represents a chemical change  The reaction takes “reactants” and changes them into “products” (a NEW substance is created) Reactant(s)  Product (s) *The arrow is read as “yields” or “produces”

Reactant(s)  Product (s) On the reactants side, bonds must be BROKEN which REQUIRES energy.  Therefore, bond breaking is an ENDOTHERMIC process

Reactant(s)  Product (s) On the products side, bonds must be FORMED which RELEASES energy  Therefore, bond forming is an EXOTHERMIC p rocess.

What about the reaction? The combination between the two sides will determine if overall the reaction is exo- or endothermic.

ENDOTHERMIC REACTION Takes more energy to break the bonds in the reactants than is released when the bonds of the products form. Surroundings will feel Cooler/Cold  Energy would be written in on the reactants side

EXOTHERMIC REACTION More energy is released when bonds of the products are formed than the energy taken to break the bonds of the reactants. Net release of energy to the surroundings…  Surroundings will feel warmer

EXOTHERMIC REACTION Where would you write the energy in the reaction for a exothermic reaction?  The products