Tiêu đề Chapter 4 Carbon and Its Compounds.pdf ✅

SCIENCE (Chemistry) Chapter 4: Carbon and its Compounds
(1) 04 Carbon and its Compounds Carbon and its Compounds Bonding in Carbon Most carbon compounds are poor conductors of electricity. From the data melting points of the carbon compounds, we find that these compounds have low melting and boiling points as compared to ionic compounds. We can conclude that the forces of attraction between the molecules are not very strong. Since these compounds are largely non-conductors of electricity, we can conclude that the bonding in these compounds does not give rise to any ions. Covalent Bond A covalent bond is formed when pairs of electrons are shared between two atoms. It is primarily formed between two same nonmetallic atoms or between nonmetallic atoms with similar electronegativity. Noble gas configuration of Carbon ● Carbon is tetravalent, it does not form ionic bond by either losing four electrons (C4+) or by gaining four electrons (C4-). It is difficult to hold four extra electron and would require large amount of energy to remove four electrons. So, carbon can form bond by sharing of its electrons with the electrons of other carbon atom or with other element and attain noble gas configuration. ● The atoms of other elements like hydrogen, oxygen and nitrogen, chlorine also form
(2) 04 Carbon and its Compounds bonds by sharing of electrons. H – H single bond between hydrogen atoms (H2) O = O double bond between oxygen atoms (O2) N ≡ N triple bond between nitrogen atoms Carbon atom has four electrons in its outermost shell. ● It requires four electrons to achieve the stable, 8 electron, inert gas configuration. ● Carbon atoms can achieve the inert gas electron arrangement only by sharing their electrons. Hence, carbon always forms covalent bonds. ● The valency of carbon is four since one carbon requires 4 electrons to achieve the nearest inert gas configuration. Thus, we can say that carbon is tetravalent. ● The four valencies of carbon are usually represented by drawing four short lines around the symbol of carbon (C).