Semiclassical black hole states and entropy

We discuss semiclassical states in quantum gravity corresponding to Schwarzschild as well as Reissner-Nordstr\"om black holes. We show that reduced quantization of these models is equivalent to Wheeler-DeWitt quantization with a particular factor ordering. We then demonstrate how the entropy of black holes can be consistently calculated from these states. While this leads to the Bekenstein-Hawking entropy in the Schwarz-schild and non-extreme Reissner-Nordstr\"om cases, the entropy for the extreme Reissner-Nordstr\"om case turns out to be zero.