Predict whether each of the following molecule has a dipole momnet
(a) `BF_(3)` (b) `IB r` (c ) `CH_(2)CI_(2)` .

Explanation

Since flurine is more electronegative than boron, each `B-F` bond in `BF_(3)` is polar and three bond moments are equal However, the symmetry of a trigonal planar shape means that the tree bond momens exactly cancel one another
(b) Since `I Br` molecule is diatomic it has a linear geometry Bromine is more electronegative than indine hence `IBr` is polar with bromine at the negative end Thus, the molecule does have a dipole moment
(c ) `CH_(2)CI_(2)` is similar to `Ch_(4)` (terahedral) but it has three different bond angles `HCH,HCCI` and `CIC CI` which are close to but not equal to `1095^(@)` Since `CI` is more electronegative than `C` and which is more electronegative than `H` the bond moments do not cancel and the molecule possesses a dipole momnet `CH_(2)CI` is thus a polar molecule
Resultant dipole moment `(R)` is indicated by

.