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