| To make any comparison of enthalpy changes a fair comparison, we must use same conditions, called ? | Standard conditions |
| What are the 3 standard conditions | - a pressure of 101kPa
- a temperature of 298 K
- each substance involved in reaction is in its normal physical state at 101 kPa and 298 K |
| What symbol (-o-) used for? | Symbol (-o-) is used to indicate that the enthalpy changes refers to a reaction carried out under standard conditions |
| Can describe enthalpy changes according to the type of chemical reaction taking place. Give 3 examples
In more general cases we can use term:? | - Enthalpy change of formation
- Enthalpy change of combustion
- Enthalpy change of neutralisation
In more general cases we can use the term
- Enthalpy change of reaction |
| Standard enthalpy change of reaction △H r ^(-o-) is what ? | Standard enthalpy change of reaction is the enthalpy change when amounts of reactants shown in stoichiometric react to give products under standard conditions. Reactants and products must be in their standard states |
| What is the symbol for Standard enthalpy change of reaction? | △Hr*^(-o-) |
| Enthalpy changes or reactions can be ? | Exothermic and endothermic |
| What is standard enthalpy change of formation? | Is the enthalpy change when 1 mole of a compound is formed from its elements under standard conditions. Reactants and Products must be in their standard states |
| What is the symbol for standard enthalpy change of formation ? | △Hf*^(-o-) |
| Enthalpy changes of formation can be? | Endothermic and exothermic |
| Standard enthalpy change of formation of any element in its standard state is ? | Zero |
| What is standard enthalpy change of combustion | The enthalpy change when one mole of a substance is burnt in excess oxygen under standard conditions
Reactant and product must be in their standard state |
| What is the symbol for standard enthalpy change of combustion | △Hc*^(-o-) |
| Enthalpy changes of combustion are always | exothermic |
| Substances combusted in standard enthalpy change of combustion can be either | elements or compounds |
| Standard enthalpy change of neutralisation is what? | Is the enthalpy change when one mole of water is formed by reaction of an acid with an alkali under standard conditions |
