Name: All About Orthophosphorous Acid
Uploaded: 2019-07-19
Duration: 13 min 22 s
Description: How is orthophosphorous acid prepared? What happens when you heat it? Too many questions! Watch the video to know everything about orthophosphorous acid.

Question

Compare and contrast the structure and behaviour of phosphates, silicates and borates.

Accepted Answer

Phosphates: Phosphate forms four equal resonating structures. It has total charge of $- 3$ and it is formed from phosphoric acid.

Phosphate group is a hypervalent molecule containing five bonds which makes ten electrons. Phosphate salts can form through ionic bonds between a cation and one of the oxygen anions. Molecules with a phosphate group are usually not very soluble in water.

Silicates: In Silicates there is no resonating structure and have total charge of $- 4$ . It is of many types, for example, Pyro silicate, Chain silicate and sheet silicate. All these are planar structures and silica has $3 - D$ structures, which is the polymer of ${SiO}_{2}$ . It is formed from silicic acid.

A silicate mineral is generally an ionic compound whose anions consist predominantly of silicon and oxygen atoms. In most minerals in the Earth's crust, each silicon atom is the center of an ideal tetrahedron, whose corners are four oxygen atoms covalently bound to it.

Borates: It is formed from boric acid and has $- 3$ charge and it also forms sodium meta borate.

Borates are the form in which boron most often occurs in nature, mainly as borate minerals and borosilicates. The incomplete octet means that Borates act as Lewis acids. When a trigonal boron atom accepts a pair of electrons from a Lewis base, it adopts a tetrahedral configuration ( ${sp}^{3}$ ), and the octet rule is satisfied. Both trigonal and tetrahedral units can co-exist in a complex borate, such as the anion in borax.

Compare and contrast the structure and behaviour of phosphates, silicates and borates.

Important Questions on The Group 15 Elements

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