A sulfuric acid solution at 25 °C has a density of 1.27 g/mL. A

Question

20.0-mL sample of this acid is measured out at 25 °C,
introduced into a 50-mL flask, and allowed to cool to 21 °C. The
mass of the flask plus solution is then measured at 21 °C. Use
the stated data, as necessary, to calculate the mass of the acid
sample.

Answer 1

density = mass x volume.
1.27 x 20.0 = ??
The remainder of the information is extraneous.

Answer 2

25.4