Question

The density of water is determined by measuring the mass of a known volume of water. If you determined the density of a 25-mL sample of water, how many significant figures should you report if you used a s instruments? (Refer to Table 1-2 for the instrument uncertainties.) (a) An analytical balance for measuring mass and a 25-ml pipet for the volume measurement (b) A centigram balance and a pipet (c) An analytical balance and a graduated cylinder (d) A centigram balance and a graduated cylinder

Answer 1

(a) for a 25 mL pipet, usually the uncertainly is ± 0,1 mL, or ± 0,05 mL. So the significant number should be at less 1.

(b) for a centigram balance, we don't need to add the significant numbers, because the unit of mass received here is in mg.

(c) the same for the last case, we don't add any significant numbers because the volume and mass obtained in uncertain.

Step-by-step explanation: