Energetics

Question 1

Exothermic

Answer 1

Chemical energy is converted into heat energy and the temperature of the system increases

Question 2

Endothermic

Answer 2

Heat energy is converted into chemical energy and the temperature of the system falls

Question 3

Enthalpy change

Answer 3

A heat energy change measured at constant pressure

Question 4

Standard conditions

Answer 4

Pressure of 100KPa, temperature of 298K

1 atm, 25•c

Question 5

Standard enthalpy of reaction

Answer 5

The enthalpy change when the number of moles of substances, as written in the equation, react under standard conditions

Question 6

Standard enthalpy of neutralisation

Answer 6

The enthalpy change when one moe of water is produced by the neutralisation of an acid by excess base under standard conditions

Question 7

Standard enthalpy of formation

Answer 7

The enthalpy change when one mole of a compound is formed from its elements under standard conditions with all reactants and products in their standard states

Question 8

Standard enthalpy of combustion

Answer 8

The enthalpy change when one of W compound is completely burned in oxygen under standard conditions with all the reactants in their standard states