I am quoting from IUPAC GOLD book$^1$ .
Meso-compound : A term for the achiral member(s) of a set of diastereoisomers which also includes one or more chiral members. For example:
There is a plane of symmetry in the examples given in IUPAC GOLD book (shown in colour) .
Molecule $\ce{3}$ also has a plane of symmetry as shown in the figure below. This makes it achiral.
Molecule $\ce{2}$ does not possess plane of symmetry , and therefore chiral.
In conclusion , molecule $\ce{3}$ is achiral and molecule $\ce{2}$ is chiral.
Refereneces
$^1$ : IUPAC. Compendium of Chemical Terminology, 2nd ed. (the "Gold Book"). Compiled by A. D. McNaught and A. Wilkinson. Blackwell Scientific Publications, Oxford (1997). Online version (2019-) created by S. J. Chalk. ISBN 0-9678550-9-8. https://doi.org/10.1351/goldbook.