Find the number of species which have net zero dipole moment

${\mathrm{PCl}}_5,{\mathrm{SF}}_4,{\mathrm{H}}_2\mathrm{O},{\mathrm{SnCl}}_2,{\mathrm{Cl}}_2$

Due to its symmetrical geometrical structure, which causes the polarity of the $\mathrm{P}-\mathrm{Cl}$ bonds to be cancelled out by one another, ${\mathrm{PCl}}_5$ is nonpolar in nature. The net dipole moment of ${\mathrm{PCl}}_5$ therefore equals zero.
There is no dipole moment in ${\mathrm{Cl}}_2$. Dipole moments, which measure the separation of charge in a molecule, are vector values that explain this.

${\mathrm{PCl}}_5,{\mathrm{Cl}}_2$