# What is the vsepr model for PCl3?

$\text{Trigonal pyramidal}$
We gots $P C {l}_{3}$, and around the central phosphorus atom there are $3 \times \text{bonding electron pairs}$, the $P - C l$ bonds, and a $\text{phosphorus-centred}$ lone pair.
To a first approximation, these electron pairs arrange themselves in a tetrahedron........with ideal bond angles of ${109.5}^{\circ}$. But we describe molecular geometry on the basis of the geometry of the ATOMS, not on the electron pairs. The symmetry descends from tetrahedral to trigonal pyramidal with $\angle C l - P - C l$ angles of approx. $100 - {103}^{\circ}$ due to the disproportionate influence of the phosphorus lone pair.