C5-Chemical Energetics Flashcards
Standard conditions
Pressure: 1atm
Temperature: 298K
Enthalpy change of formation
Energy change when 1 mol compound is formed
from its elements in their standard states
under standard conditions of 1 atm and 298K.
Enthalpy change of combustion
Energy change when 1 mol substance is
burnt completely in excess O2
under standard conditions of 1 atm and 298K.
Enthalpy change of atomisation
Energy change when an element / compound is
converted into 1 mol free gaseous atoms
under standard conditions of 1 atm and 298K.
Bond energy
Energy required to break 1 mol covalent bonds between 2 gaseous atoms.
Hess’ law
Overall change of reaction is equal
regardless of routes by which the reaction occurs
as long as initial and final conditions are equal.
Which alkane is gas at room temperature?
Methane, ethane, propane, butane
Which alkene is gas at room temperature?
Ethene, propene, butene
