Molten carbonates and other molten salts have potential applications as diverse as fuel cells, CO2 sequestration and other energy applications. Understanding the structure and dynamics of these liquids on an atomistic level is critical if these important applications are to be realised. Studies of molten sodium carbonate have been completed using in situ diffraction techniques combined with advanced molecular dynamics simulation. The simulations make specific predictions about the diffusion of sodium in these molten salt liquids. In this proposal we aim to establish the diffusion characteristics of molten sodium carbonate using the QENS technique. Sodium carbonate is an ideal system for this measurement since the contributions from the carbonate anions will be completely coherent while the incoherent contribution from the sodium ion movements will dominate the QENS signal.