How do you measure the mass of 200 ml of water? - Answers

Mass is measured in grams, kilograms, etc. We know that 1 ml of water has a mass of approximately 1 gram,* so we should expect the water to have a mass of approximately 200 grams. To determine the mass of 200 ml of an actual quantity of water, we would have to weight it. Technically we would have to convert from weight to mass, but in fact, most scales are given with units that express mass, so in effect this conversion has been done already using certain assumptions about the gravitational field being experienced when the weighing takes place. You can weigh your 200 ml of water in a container and then subtract the weight of the container to determine the weight of the water. *To be exact, 1 milliliter or 1 cubic centimeter of pure water at 4 degrees Celsius has a mass slightly less than 1 gram; in fact, it used to have that value by definition. However, when the kilogram was redefined, that exact relationship was lost. See the link for details.