CEM 142 EXAM 2 LATEST UPDATE GRADED A+

CEM 142 EXAM 2 LATEST UPDATE GRADED A+ **ACID = ELECTRON PAIR ACCEPTOR Acid= electrophile **BASE = ELECTRON PAIR DONOR base= nucleophile strong acid fully ionizes in solution/completely dissociates weak acid does not fully ionize or dissociate into ions ** negatively charged ion --- wants to loose 1 electron can tell if a solution is ionized when... a fully ionized solution will conduct more electricity than a non fully ionized solution strength of acid depends on...(4 things) 1) the strength of the H-X bond 2) the enthalpy change when added to water 3) the entropy change when added to water 4) the stability of the X- conjugate base Enthalpy (delta H) ** breaking a bond is endothermic and enthalpy is positive **forming bonds is exothermic and enthalpy is negative---energy is released when new bonds form - enthalpy is positive in endothermic reactions or when heat energy is absorbed -enthalpy is negative in exothermic reactions or when heat energy is released why delta H or enthalpy is higher for different bonds is due to bond enthalpy bond enthalpy= energy it takes to break a bond in the gas phase - how strong a bond is bond enthalpy is in KJ/mol how strong a bond is depends on... -Ex) HF has a higher bond energy than other bonds because of this F, for example, has a smaller atomic radius, and atoms will be closer together. there will be better overlap of the bonding orbitals have an increase in atomic radius to going to the left of the row (---- ) and will increase going down the column