Carbon belongs to IVA group along with 4 other elements (Silicon, Germanium, Tin & Lead). Electronic configuration of carbon is
1s2, 2s2, 2p2
It is a p-block element.
Metal exist in the different form in nature which is different in physical properties but similar in chemical properties. Such phenomenon of existence in nature is known as allotropy.
The different allotropic forms of carbon are
It is sp3 hybridized carbon atom covalently bonded to other 4 carbon atom to form a regular tetrahedron with a bond angle of 109°28'. All the carbon atoms are covalently bonded throughout the crystal which makes it so hard. Since the carbon-carbon bond is uniform and short, the whole crystal becomes strong (Bond length = 1.54 Aº & 1Aº= 10-8). Since, all four electron carbon atom are used to form the covalent bond, no any free electron is left so it is unable to conduct electricity.
It is sp2 hybridized carbon atom bonded to other 3 carbon atom to hexagonal network with a bond angle of 120°. Layers of graphite are bonded with weak Vanderwall force. Since, one layer of graphite slip over another, it is soft & slippery and hence also used as the lubricant. Since graphite has one free electron, it is able to conduct electricity.
Carbon-carbon bond length = 1.42 Aº & 1Aº= 10-6 cm
Bond angle =120°
Successive layer = 3.40 Aº
It is latest discovered crystalline allotrope of carbon. It is nearly spherical containing 60 atoms of carbon covalently bonded to each other & looks like the soccer ball and called bulky ball & cell known as “Buck Minister Fullerene”. It has 12 pentagonal and 20 hexagonal forces and it shows superconductivity.
Coal:It is obtained by slow decomposition of wood or green matter under the effect of heat, pressure& limited supply of air. It helps to manufacture producer gas (CO + N2) & water gas (CO + H2).
Coke:It is the purest amorphous greyish black liquid form of carbon obtained by destructive distillation of coal. It can be used as the reductant in metallurgy.
Charcoal:It is obtained by destructive distillation of wood, sugar, bone etc. It is the porous form of carbon. It can be used to absorb toxic gas & purify liquid.
Types of Charcoal
In the lab, carbon monoxide (CO) is prepared by heating oxalic acid crystal ((COOH)22H2O) with concentrated sulphuric acid (H2SO4).
The gases are passed through the aqueous solution of caustic soda (NaOH) so that carbon dioxide (CO2) is occupied & carbon monoxide (CO) is freely found.
$$Fe+5CO\longrightarrow Fe(CO)_5 (Iron\space carbonyl)$$
$$Ni+4CO\longrightarrow Ni(CO)_4 (Nickel\space carbonyl)$$
$$CO+4CO\longrightarrow CO(CO)_4 (Cobalt\space carbonyl)$$
$$Fe_2O_3+3CO\longrightarrow 2Fe+3Co_2 (Ferric\space oxide\space to\space iron)$$
$$ZnO+CO\longrightarrow Zn+CO_2 (Zinc\space oxide\space to\space zinc)$$
The solid form of CO2 is known as dry ice. It is called so because it is similar to ice but doesn’t wet cloth or paper when placed onto them.
Pulse, Tracy. Introduction to chemistry. u.s.a: flex book, 2010.
Pathak, Sita Karki. The Text Book of Chemistry. kathmandu: Vidhyarthi Pustak Bhandar, 2012.