Which is more accurate? Massing or to determine the volume first?

Question

Which is more accurate, to mass the liquid in the small container before pouring it into the graduated cylinder, or to determine its volume first?

Answer 1

The answer depends on what you are using to measure with. Assuming arbitrary accuracy in the instruments, that leaves systematic error.

For measuring mass, minimizing systematic error would involve carefully subtracting the tare of the small container. For measuring volume, is would involve making sure all of the liquid was transferred to the graduated cylinder and then deciding where on the meniscus to measure the volume. All things being equal, I would have to say that the mass measurement has the potential for less systematic error. There will always be a thin film left in the original container and there is no practical way to compensate the volume measurement for the curvature of the meniscus.

Answer 2

Not sure what you're doing but I think I would watch the graduations in the graduated cylinder and go by that.