Constants Periodic Table v Part A Molecules can be polar because of the unsymmet
ID: 715680 • Letter: C
Question
Constants Periodic Table v Part A Molecules can be polar because of the unsymmetrical distibution of electrons. The dipole moment, , is a measure of the net polarity and is defined as the charge 1.89x102 C. in coulombs, times the distance between the charges, which is estimated by the bond length, r, in meters: The dipole measured for HI is 0.380 D. The bond length is 181 pm. What is the percent ionic character of the HI bond? Express your answer as a percent to three significant figures. View Available Hintfs) The SI unit of dipole moment is the coulomb-meter m), but another common unit is the debye (D). two are related as %ionic character 5.7 3.336 x 10-30 C-m- 1 D The percent ionic character is a comparison of the measured dipole to the expected dipole: Submit % ionic character measured dipole x 100% expected dipole X Incorrect; Try Again; 4 attempts remaining The expected dipole is one for which a full unit of charge (1.60 × 10 19 C) exists on each end of the bond v Part B Describe the molecular dipole of OCIz View Available Hintfs) The molecular dipole i SubmitExplanation / Answer
part -a
Expected dipole moment = 1.60 X 10-19 X 161 X 10-12 C-m
= 256.7 X 10-31 C-M
since we know that 3.335 X 10-30 C-m = 1 D
therefore, expected dipole moment =( 256.7 X 10-31)/ (3.335 X 10-30) D =7.69 D
percentage ionic character = (0.380/7.69) X 100= 4.94 %
part - b
OCl2 is a polar molecule because there is electronegetivity difference between Oxygen and Chlorine
Electronegetivity of Chlorine is 3.16 and that of Oxygen is 3.44. therefore the molecule will have a measurable dipole moment and the direction of the dipole moment will be towards the Oxygen atom.
part c-
let us suppose that the bond length is x metre, therefore,
we know that
ionic character =( measured dipole moment/ expected dipole moment) X 100
therefore, 11.8 = [(0.797 X 3.34 X 10-30) / (1.602 X 10-19 X x metre)]X 100
x = 0.1408 X 10-9m
x = 140.8 pm