topic 6 ( energetics

Question 1

standard enthalpy change of reaction

Answer 1

The enthalpy change that occurs when the equation quantities of materials react under standard conditions

Question 2

standard enthalpy change of combustion

Answer 2

enthalpy change measured at standard conditions, when one mole of a substance is completely burned in oxygen.

Question 3

standard enthalpy change of neutralisations

Answer 3

When one mole of water is produced by the neutralisations of an acid with an alkali

Question 4

STEC of formation

Answer 4

When one mole of a substance is formed, its elements are in their standard states

Question 5

hess law

Answer 5

the law states that the enthalpy change of a reaction is independent of the path taken in converting reactions into products, provided the initial and final conditions are the same in each case

Question 6

bond enthalpy

Answer 6

when one mole of a bond in the gas state is broken

Question 7

mean bond enthalpy

Answer 7

One mole of a bond, averaged out over many different molecules, is broken