A carboxylic acid can exist in two conformations E and Z that are different by the dihedral angle around the C-O bond. Recent theoretical calculations indicate that the Z conformer of formic acid is 4.04 kcal/mol (Tetrahedron, 2004, 60, 179-185) more stable than the corresponding E conformer. Assuming that the pKa of the Z conformer of formic acid is equal to 3.77, calculate the pKa of the E conformer of formic acid. Assume that ?G=1.4*pKa kcal/mol.