5.2 energetics

Question 1

in an endothermic reaction, heat energy is ________ and ∆H is ________. This means that the products end up with ____ energy than the reactants had.

Answer 1

in an endothermic reaction, heat energy is absorbed and ∆H is positive. This means that the products end up with more energy than the reactants had.

Question 2

in an exothermic reaction, heat energy is ________ and ∆H is ________. This means that the products end up with ____ energy than the reactants had.

Answer 2

in an exothermic reaction, heat energy is released and ∆H is negative. This means that the products end up with less energy than the reactants had.

Question 3

what is the enthalpy change?

Answer 3

the heat energy a reaction releases or absorbs per mole

Question 4

what unit is enthalpy change?

Answer 4

kJ/mol

Question 5

what’s the equation for enthalpy change involving making and breaking bonds?

Answer 5

∆H = bonds broken - bonds made

Question 6

bond breaking _______ heat energy

Answer 6

bond making absorbs heat energy

Question 7

bond making _________ heat energy

Answer 7

bond making releases heat energy