Given below are statements about some molecules/ions. Identify the CORRECT statements. A. The dipole moment value of NF _ 3 is higher than that of NH _ 3 . B. The dipole moment value of BeH _ 2 is zero. C. The bond order of O _ 2 ^ 2- and F _ 2 is same. D. The formal charge on the central oxygen atom of ozone is -1. E. In NO _ 2 , all the three atoms satisfy the octet rule, hence it is very stable. Choose the correct answer from the options given below:
C. B & C Only
Statement A: In NH_3, the orbital dipole due to the lone pair is in the same direction as the resultant dipole moment of the N-H bonds. In NF_3, the orbital dipole is in the opposite direction to the resultant dipole moment of the N-F bonds. Thus, dipole moment of NH_3 (1.47\ D) is higher than NF_3 (0.23\ D). Statement A is incorrect. Statement B: BeH_2 is a linear molecule (sp hybridization). The two Be-H bond dipoles are equal and opposite, so they cancel each other out, making the net dipole moment zero. Statement B is correct. Statement C: O_2^ 2- has 18 electrons. Its bond order is 10-8 2 = 1. F_2 also has 18 electrons and its bond order is 1. Statement C is correct. Statement D: In the Lewis structure of ozone (O_3), the central oxygen atom forms one double bond and one single bond and has one lone pair. Formal charge = V - L - B 2 = 6 - 2 - 6 2 = +1. Statement D is incorrect. Statement E: NO_2 is an odd-electron molecule (17 valence electrons). The nitrogen atom has only 7 electrons in its valence shell, so it does not satisfy the octet rule. Statement E is incorrect. Therefore, only statements B and C are correct.
Related: Chemistry — Chemical Bonding and Molecular Structure · All PYQ Banks