Ncer -class 11- Chemistry- unit 4- Chemical Bonding and Molecular Structure Welcome to your Ncer -class 11- Chemistry- unit 4- Chemical Bonding and Molecular Structure 1. Which of the following molecules has dipole moment greater than zero? 3-3-Diethylpentane 2,2,3,3-tetramethyl butane Neopentane trans-2-pentene None 2. The correct order of increasing bond length of C−H, C−O, C−C and C=C is : 𝐶 − 𝐻 < 𝐶 = 𝐶 < 𝐶 − 𝑂 < 𝐶 − 𝐶 C−H < C=C < C−O < C−C 𝐶 − 𝑂 < 𝐶 − 𝐻 < 𝐶 − 𝐶 < 𝐶 = 𝐶 C−O < C−H < C−C < C=C C−H < C−O < C−C < C=C 𝐶 − 𝐶 < 𝐶 = 𝐶 < 𝐶 − 𝑂 < 𝐶 − 𝐻 C−C < C=C < C−O < C−H None 3. Select the correct statement : $$ X_{e}F_{5}^{+}$$ has disorted octahedral geometry First ionization energy of Al is greater than that of gallium If molecule has any polar bond, then it is always polar Solubility of noble gases increases in water down the group when their size increases because London dispersion force increases None 4. Which of the following is diamagnetic? Superoxide ion Oxygen molecule None of these Carbon molecule None 5. Which bond properties are consistent with one another? Bond order- Lower, Bond length - shorter, Vibrational frequency- lower Bond order- Higher, Bond length- longer, Vibrational frequency - lower Bond order- Lower, Bond length- longer, Vibrational frequency - higher Bond order- Higher, Bond length- Shorter, Vibrational frequency- higher None 6. As compared to covalent compounds, electrovalent compounds generally have High melting points and high boiling points Low melting points and high boiling points Low melting points and low boiling points High melting points and low boiling points None 7. The number and types of bonds between two carbon atoms in calcium carbide is: one sigma, two pi two sigma, two pi tow sigma, one pi one sigma, one pi None 8. Which of the following species has maximum dipole moment $$𝐶𝐻_{3} I $$ $$𝐶𝐻_{3} Br $$ $$𝐶𝐻_{3}𝐹$$ $$𝐶𝐻_{3} Cl $$ None 9. The paramagnetic nature of oxygen molecule is best explained on the basics of Valence bond theory Resonance Molecular orbital theory Hybridisation None 10. What type of bond is formed if atom looses one or more valence electrons to give positive metal ions? Hydrogen bonding Polar covalent Ionic Metallic None 11. The values of electronegativity of atoms A and B are 1.20 and 4.0 respectively. The percentage of ionic character of A and B bond is 43% 50% 55.3% 72.24% None 12. In the formation of hydrogen molecule, overlapping of atomic orbitals occur which results in the pairing of electrons. These are: valence shell electrons with opposite spins. lone pair of electons valence shell electrons with same spins valence shell electrons irrespective of the spins None 13. The order of number of lone pair of xenon in following compound is. $$X_{e} OF_{6} >X_{e} O F_{4} > X_{e} OF_{3} $$ $$X_{e} F_{6} >X_{e} O F_{4} > X_{e} O_{3} $$ $$ X_{e} F_{2} >X_{e} F_{4} > X_{e} O_{3} > X_{e} O_{4}$$ $$X_{e} F_{6} >X_{e} O F_{4} > X_{e} O_{3} > X_{e} O_{4}$$ None 14. Chlorine does not show hydrogen bonding in its compounds while nitrogen shows hydrogen bonding in its compounds. Identify the correct reason. Chlorine has larger size than nitrogen 𝐻−𝐶𝑙 bond is stronger than N−H bond Chlorine has vacant d-orbitals while nitrogen has no vacant 'd' sub shell Chlorine is not as highly electronegative as nitrogen None 15. Which of the following compound has four bond pair and one lone pair? $$NH_{4}^{+}$$ $$X_{e}F_{4}$$ $$SF_{4}$$ $$ICI_{4}^{-}$$ None 16. Lone pair of electrons are electrons in orbitals? Which does not undergo hybridization Which undergoes hybridisation and participate in Bond formation Which undergo hybridization but not participate in Bond formation Which undergoes hybridization None 17. Which of the following molecule does not possess a permanent dipole moment? $$SO_{2}$$ $$SO_{3}$$ $$CS_{2}$$ $$H_{2}S$$ None 18. The amount of energy required to break one mole of bonds of a particular type between two atoms in a gaseous state is called ionization enthalpy Electron affinity lattice enthalpy bond enthalpy None 19. Which of the following is not correct? A double bond is stronger than a single bond A double bond is stronger than a single bond A sigma bond is weaker than 𝜋 𝑏 𝑜 𝑛 𝑑 A sigma bond is weaker than π bond A sigma bond is stronger than 𝜋 𝑏 𝑜 𝑛 𝑑 A sigma bond is stronger than π bond A double bond is shorter than a single bond A double bond is shorter than a single bond None 20. The number of unpaired electrons in paramagnetic diatomic molecules of an element with atomic number 16 is? 1 4 2 3 None Time's up Please Share This Share this content Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Leave a Reply Cancel replyCommentEnter your name or username to commentEnter your email address to commentEnter your website URL (optional) Save my name, email, and website in this browser for the next time I comment.
