The equilibrium for the reversible decomposition of formic acid into carbon dioxide and hydrogen is studied ill the ionic liquid (IL) 1,3-dipropy1-2-methylimidazolium formate. The equilibrium is strongly favored to the formic acid side because of the Strong solvation of formic acid in the IL through the strong Coulombic solute-solvent interactions. The comparison of the equilibrium constants in the IL and water has shown that the pressures required to transform hydrogen and carbon dioxide into formic acid can be reduced by a factor of similar to 100 by using the IL instead of water. The hydrogen transformation in such mild conditions call be a chemical basis for the hydrogen storage and transportation using formic acid.