Anirudh Walia is teaching live on Unacademy Plus
Chemical Properties of Group 14 Elements (a) Hydrides All members of the group form covalent hydrides. Their number and ease of formation decreases down the group Hydrides of carbon are called hydrocarbons (alkanes, alkenes or alkynes). Hydrides of Si and Ge are known as silanes and germanes The only hydrides of Sn and Pb are SnH4 (stannane) and PbH4 (plumbane), Their thermal stability decrease down the group. Their reducing character increases down the group.
(ii) Halides All the elements give tetrahedral and covalent halides of the type MX4 except PbBr4, and Pbl4 Thermal stability Order of thermal stability with common metals Except CX4 other tetrahalides can hydrolysed due to the presence of vacant d-orbitals. SiX4 2H20 SiO2 4Hx. ease of hydrolysis: SiX4> GeX4> SnX4> PbX4
(iii) Oxides They form two types of oxides. mono-oxides of the type MO. eg, CO (neutral) and SiO, GeO. SnO. PbO(all basic) and dioxides of the type MO2 CO2 is linear gas at ordinary temperature. Solid CO2 is known as dry ice or drikold ilk SiO2 is a solid with three dimensional network in which Si is bonded to four oxygen atoms tetrahedrally and covalently. A mass of hydrated silica (SiO2) formed from skeletons of minute plants, known as diatoms, is called kieselguhr. It is a highly parous material and is used in the manufacture of dynamite.