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Flashcards in Energetics Deck (13):
1

exothermic

chemical reactions where heat is given out

2

endothermic

chemical reactions where heat is taken in

3

what is the enthalpy change?

the change in energy

4

what are the units for enthalpy?

kJ/mol

5

if a reaction is exothermic, the enthalpy value is...

negative: the reaction is GIVING OUT energy

6

if a reaction is endothermic, the enthalpy value is...

positive: the reaction is TAKING IN energy

7

catalysts...

lower the activation energy

8

enthalpy change=

total energy absorbed to break bonds - total energy released in making bonds

9

bond breaking=

endothermic

10

bond making=

exothermic

11

enthalpy (using a calorimeter)=

4.2 x mass of solution x change in temperature (of the water)

12

energy change per mol=

-heat enthalpy/number of moles of fuel used

13

number of moles of fuel used=

mass of fuel/Mr