Question

given this table of electronegativities: atom electronegativity h 2.2 c 2.6 n 3.0 o 3.4 f 4.0 s 2.6 br 3.0 cl 3.2 p 2.2 i 2.7 list the following molecules in order of increasing dipole moment: ni₃, co₂, hi, nh₃

Explanation:

Step1: Determine molecular geometry and polarity

• $CO_2$ is linear ($O = C=O$), non - polar as bond dipoles cancel out, so its dipole moment is 0.
• $NI_3$ has a trigonal pyramidal geometry. N (3.0) and I (2.7) have a small electronegativity difference.
• $HI$ is a diatomic molecule with H (2.2) and I (2.7), has a polar bond.
• $NH_3$ has a trigonal pyramidal geometry. N (3.0) and H (2.2) have a relatively large electronegativity difference.

Step2: Calculate electronegativity differences

• For $NI_3$: $\Delta\chi=3.0 - 2.7 = 0.3$.
• For $HI$: $\Delta\chi=2.7 - 2.2 = 0.5$.
• For $NH_3$: $\Delta\chi=3.0 - 2.2 = 0.8$.

Step3: Arrange in order of increasing dipole moment

Since $CO_2$ has 0 dipole moment, and considering the electronegativity differences and molecular geometries, the order is $CO_2

Answer:

$CO_2