1x4=4 2. Read the passage given below and answer the questions given below it: The tetravalency of carbon and the formation of covalent bonds by it are explained in terms of its electronic configuration and the hybridization of s and p-orbitals. The formation and the shapes of molecules like methane (CH), ethene (CH,) and ethyne (CH) are explained in terms of the use of sp, sp and sp hybrid orbitals by carbon atoms in the respective molecules. Hybridization influences the bond length and bond strength in compounds. The sp hybrid orbital contains more s character and hence it is closer to its nucleus and forms shorter and stronger bonds than the sphybrid orbital The sp hybrid orbital is intermediate in s character between sp and spand, hence, the length and enthalpy of the bond, it forms, are also intermediate between them. The change in hybridization affects the electronegativity of carbon. The greater the s character of hybrid orbitals, the greater is the electronegativity. Thus a carbon atom having an sp hybrid orbital with 50% s character is more electronegative than that possessing sp or sp hybrid orbitals. In following questions, a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices : (a) Assertion and reason both are correct statements and reason is correct explanation for assertion. (b) Assertion and reason both are correct statements but reason is not correct explanation for assertion. (c) Assertion is correct statement but reason is wrong statement (d) Assertion is wrong statement but reason is correct statement (i) Assertion : The shape of methane molecule is tetrahedral. Reason : It possesses sp hybridization. (ii) Assertion : The sp hybrid orbital form shorter and stronger bonds than the sp hybrid orbital. : The sp hybrid orbital contains more s character. (iii) Assertion : The length and enthalpy of the bonds formed by sp hybrid orbital are intermediate between sp and sp hybrid orbitals. Reason : The sp² hybrid orbital has more s character than sp hybrid orbital. (iv) Assertion : The greater the s character of hybrid orbitals, the greater is the electronegativity. Reason : The change in hybridization influences the electronegativity of carbon. OR Assertion : The sp hybrid orbital is closer to its nucleus. : The sp hybrid orbital contains less s character. Reason Reason
Answers
Answer:
1) b ,it's sp3
2) a
3) assertion is not clear,reason is wrong
4)d or c
The answer to the given question is follows:
(i). Assertion: The shape of the methane molecule is tetrahedral.
Reason: It possesses sp² hybridization.
Ans: The shape of the methane molecule is tetrahedral as it possesses sp³ hybridization. So, the assertion is the correct statement but the reason is the wrong statement, (C).
(ii). Assertion: The sp hybrid orbital form shorter and stronger bonds than the sp³ hybrid orbital.
Reason: The sp hybrid orbital contains more s character.
Ans: The sp hybrid orbital contains more s character than sp³ hybrid orbital so the sp hybrid orbital forms shorter and stronger bonds than the sp³ hybrid orbital. So, the assertion and reason both are correct statements and reason is the correct explanation for the assertion, (A).
(iii). Assertion: The length and enthalpy of the bonds formed by sp hybrid orbital are intermediate between sp and sp hybrid orbitals.
Reason: The sp² hybrid orbital has more s character than the sp hybrid orbital.
Ans: The sp² hybrid orbital is intermediate in s characters between sp² and sp³ hybrid orbitals. So, the assertion and reason both are correct statements but the reason is not the correct explanation for the assertion, (B).
(iv). Assertion: The sp hybrid orbital is closer to its nucleus.
Reason: The sp hybrid orbital contains less s character.
Ans: The sp hybrid has more s character. So, the assertion is correct statement but reason is wrong statement, (C).