Energetics

Question 1

Standard conditions

Answer 1

100kPa, 298K

Question 2

Enthalpy change

Answer 2

Heat energy change at constant pressure

Question 3

Positive enthalpy change means the reaction is …

Answer 3

Endothermic

Question 4

Negative enthalpy change means the reaction is …

Answer 4

Exothermic

Question 5

Endothermic reaction

Answer 5

Reaction where heat is taken in

positive enthalpy change

Question 6

Exothermic reaction

Answer 6

Reaction where heat is given out

negative enthalpy change

Question 7

Standard enthalpy change of reaction

Answer 7

Enthalpy change for the smallest whole number ratio of a reaction at standard states and conditions

Question 8

Standard enthalpy change of formation

Answer 8

Enthalpy change to form 1 mole of a compound out of its elements at standard states and conditions

Question 9

Standard enthalpy change of combustion

Answer 9

Enthalpy change to combust 1 mole of a fuel at standard states and conditions

Question 10

Standard enthalpy change of neutralisation

Answer 10

Enthalpy change to form 1 mole of water from a neutralisation reaction at standard states and conditions

Question 11

Energy transferred to / from a material

Answer 11

Energy = mass*specific heat capacity*temp change
(E = mcΔT)

Question 12

Hess law

Answer 12

Enthalpy change depends on the chemicals, not the reactions

Question 13

Bond enthalpy

Answer 13

Energy needed to break 1 mole of a bond in the gas state

Question 14

Mean bond enthalpy

Answer 14

Energy needed to break 1 mole of a type of bond in the gas state, averaged over many compounds