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