Not all the tap water in China is potable. Dot drink tapped water other than the pre-boiled water supplied in your hotel room, as the natural enzymes in local water supplies are different to those your body is used to at home and may cause some temporary upset. Bottled water is available everywhere.
Electricity supply in China and Asia is 220 volts, but sockets with adapters are available in the washrooms of many luxury and medium-grade hotels. If they are not availabel in the washroom, ask the reception to send one to your room. The following sockets are most commonly used in Chinese hotels, offices and families.