A closed, rigid steel tank has an inner volume of 0.02832m³ and has a mass of 22.7 kg when empty. Initially, the tank contains 0.45 kg of water (liquid plus vapor), and the tank and the water are both at 294 K. The tank containing the water is then placed on a 45 kg slab of steel, which is at another temperature. Assume the tank–water–slab system comes to equilibrium with no heat transfer to the surroundings. The final temperature of the tank water slab system is 555 K. The specific heat of the steel in both the tank and the slab is 0.419 kJ/kg · K. Determine the initial slab temperature (K).