Assertion :SiC has higher melting point that NaCl. Reason: SiC has stronger electronic forces of attraction.
Assertion :SiC has higher melting point that NaCl. Reason: SiC has stronger electronic forces of attraction.
The correct option is C Assertion is correct but Reason is incorrect
SiC has a tetrahedron structure (resembling CH4). If we substitute 4−H atoms in CH4 by Si, we have a molecule of SiC. They are held by a covalent bond with carbon. But, there is also a slight ionic bond created as well. The carbon atom becomes slightly negative and the silicon atom becomes slightly negative and Si atom becomes slightly positive. These polar qualities developed has similarity to that of H2O molecule. This interaction is responsible to adhere to various layers of a tetrahedron of SiC strongly to each other. So, the melting point of SiC is high because a great amount of heat is required to overcome such interactions.
NaCl, on the other hand, is a strong ionically bonded molecule but since there is no such polar quality as that of SiC. So, its melting point is less.
SiC has a tetrahedron structure (resembling CH4). If we substitute 4−H atoms in CH4 by Si, we have a molecule of SiC. They are held by a covalent bond with carbon. But, there is also a slight ionic bond created as well. The carbon atom becomes slightly negative and the silicon atom becomes slightly negative and Si atom becomes slightly positive. These polar qualities developed has similarity to that of H2O molecule. This interaction is responsible to adhere to various layers of a tetrahedron of SiC strongly to each other. So, the melting point of SiC is high because a great amount of heat is required to overcome such interactions.
NaCl, on the other hand, is a strong ionically bonded molecule but since there is no such polar quality as that of SiC. So, its melting point is less.
