Final answer:
The tank contains 5000 L of water, and since liters is a unit of volume, this is the volume of water in the tank.
Step-by-step explanation:
The student's question asks about the volume of water in a tank which already states that it contains 5000 L of pure water. Considering the information given, the volume of water in the tank is 5000 L. The unit 'L' refers to liters, which is a unit of volume commonly used for liquids.