Question

(a) Write the balanced chemical equation for the reaction of `Cl_(2)` with hot and concentrated `NaOH`. Is this reaction a disproportion reaction?
(b) when `HCl` reacts with finely powdered iron, it forms ferrous chloride and not ferric chloride. why?
Deduce the molecular shape of `BrF_(3)` on the basis of `VSEPR` theory.

Answer 1

`overset((0))3Cl_(2)+6NaOH rarr 5Naoverset((-1))(Cl)O_(3)+3H_(2)O`
Yes, chlorine from zero oxidation state is reduced to `-1` and oxidised to `+3` oxidation states.
(b) `HCl` reacts with `Fe` to produce `H_(2)` gas
`Fe+2HCl rarr FeCl_(2)+H_(2)`
Liberation of `H_(2)` prevents the formation of ferric chloride, `FeCl_(3)`.
(c ) The central atom `Br` in `BrF_(3)` has seven electrons in the valence shell. Three of these will form electron pair bonds with three fluorine atoms leaving behind four electrons. Thus, there are three bond pairs and two lone pairs. According to `VSEPR` theory, these will occupy the coners of trigonal bipyramid. The two lone pairs will occupy the equatorial positions to minimise lone pair and the bond pair-lone pair repulsions which are greater than the bond pair-bond pair repulsions. In addition, the axial fluorine atoms will be bent towards the equatorial fluorine in order to minimise the lone pair-lone pair repulsions. The shape would be of slightly bent `T`