Why are lattice energy and enthalpy defined using opposite signs?
The lattice energy and enthalpy defined using opposite signs as the energy required to convert the crystal into infinitely separated gaseous ions in vacuum, an endothermic process. Following this convention, the lattice energy of NaCl would be +786 kJ/mol. The lattice energy for ionic crystals such as sodium chloride, metals such as iron, or covalently linked materials such as diamond is considerably greater in magnitude than for solids such as sugar or iodine, whose neutral molecules interact only by weaker dipole-dipole or van der Waals forces.
How to Calculate Outer Pressure of Lattice?
Outer Pressure of Lattice calculator uses Pressure Lattice Energy = (Lattice Enthalpy-Lattice Energy)/Molar Volume Lattice Energy to calculate the Pressure Lattice Energy, The Outer pressure of lattice is the pressure of lattice against which the lattice enthalpy further takes into account that work has to be performed. Pressure Lattice Energy is denoted by pLE symbol.
How to calculate Outer Pressure of Lattice using this online calculator? To use this online calculator for Outer Pressure of Lattice, enter Lattice Enthalpy (ΔH), Lattice Energy (U) & Molar Volume Lattice Energy (Vm_LE) and hit the calculate button. Here is how the Outer Pressure of Lattice calculation can be explained with given input values -> 800 = (21420-3500)/22.4.