What is the approximate weight of 200 liters of water?

The approximate weight of 200 liters of water is 200 kg because one liter of water has a mass of about 1 kilogram at standard temperature and pressure. Therefore, if you have 200 liters of water, the weight can be calculated directly by recognizing that 1 liter corresponds to 1 kg. Thus, multiplying the volume (200 liters) by the mass per liter (1 kg) gives you a total mass of 200 kg. This simple relationship stems from the definition of a liter as a measure of volume equivalent to 1 cubic decimeter, where water achieves its maximum density, making this conversion straightforward and reliable for typical purposes.