One liter of water at 50 C has kinetic energy as 2 liters of water at 50 C?

Well, technically speaking, kinetic energy is directly proportional to mass and temperature. So, if both quantities of water are at the same temperature, then the one with greater mass will have more kinetic energy. In this case, one liter of water will have half the kinetic energy of two liters of water at the same temperature.