Developing fuels definitions

Question 1

Activation energy

Answer 1

The minimum energy required for a reaction to take place.

Question 2

Exothermic reactions

Answer 2

They are often spontaneous reactions and release energy to surroundings, resulting products having lower energy than reactants.

Question 3

Endothermic reactions

Answer 3

They take in energy from the surroundings and products have more energy than reactants.

Question 4

Standard enthalpy change of combustion and the value.

Answer 4

The enthalpy change when one mole of a substance is burnt completely in oxygen under standard conditions.
The value is always:
-2802KJmol-1

Question 5

Standard enthalpy change of formation and the value.

Answer 5

The enthalpy change when one mole of a compound is formed from its elements in their standard states under standard conditions.

-74.8KJmol-1
Zero

Question 6

Standard enthalpy change of neutralisation

Answer 6

Enthalpy change when 1 mole of H+ ions reacts with 1 mole of OH- ions forming one mole of water under standard conditions and in solutions of 1moldm-3.

Question 7

Standard conditions

Answer 7

1atm
298K (25C)
1moldm-3

Question 8

Average bond enthalpy

Answer 8

Enthalpy change of breaking one mole of bonds in gaseous molecules.