-6969 Kj/mol2
n-butane: -140.7 kJ/mol (liq.) & -124.7 kJ/mol (gas)isobutane: -158.4 kJ/mol (liq.) & -134.5 kJ/mol (gas)
i believe that standard enthalpy change of atomisation is the enthalpy change that takes place when one mole of gaseous atoms is formed from its elements under standard conditions(which includes breaking of bonds between atoms within molecules), while for sublimation it only involves the change of states (from solid to liquid) with no intramolecular bonds broken.
Enthalpy is a state function, and to a first approximation does not depend on temperature. So the change in enthalpy to go from solid to a gas directly (sublimation) at some temperature is equal to the sum of the enthalpies associated with going from a solid to a liquid (fusion) and going from a liquid to a gas (vaporization) at other temperatures.
The heat energy, or enthalpy, associated with a solid to liquid transition is the enthalpy of fusion and that associated with a solid to gas transition is the enthalpy of sublimation.
The standard enthalpy for sodium sulphate is -1387kJ/mol.
The enthalpy of N2 at standard conditions is 0 kJ/mol.
The standard enthalpy of formation is the energy change when one mole of a compound is formed from its elements in their standard states. The standard enthalpy of reaction is the energy change for a reaction under standard conditions. The relationship between the two is that the standard enthalpy of reaction is the sum of the standard enthalpies of formation of the products minus the sum of the standard enthalpies of formation of the reactants.
The standard enthalpy of formation for N2 gas is 0 kJ/mol.
delta Hr is the enthalphy change of a reaction delta Hf is the enthalpy of formation where one mole of a substance is formed ( generally in its naturally occurring physical state) delta Hc is the enthalpy of combustion where one mole of a substance in its standard state undergoes combustion delta Hn is the enthalpy of neutralization where one mole of H+ reacts with OH- to form one mole of H2O delta Ha is the enthalpy of atomization where a molecule splits to form its neutral atomic components
Oxygen gas (O2) does not have an enthalpy of formation because it is an element in its standard state, which has an enthalpy of formation of zero by definition. Ozone (O3), on the other hand, is a compound and has a defined enthalpy of formation because it is formed from its elements in their standard states.
The standard enthalpy change of vaporization for CDDT (Clotrityl chloride) is approximately 42 kJ/mol.
Water is identical to the standard enthalpy change of combustion of hydrogen because the combustion of hydrogen involves its reaction with oxygen to form water. The standard enthalpy change of this reaction is defined by the energy released when hydrogen combusts completely, which results in the formation of water as a product. Thus, the formation of water from hydrogen and oxygen under standard conditions directly correlates to the enthalpy change associated with the combustion process. Hence, the enthalpy change for the formation of water from its elemental components is equivalent to the enthalpy change of hydrogen combustion.