Question

which of the following is a non - polar molecule? \\(\circ\\) \\(\ce{h_{2}o}\\) \\(\circ\\) \\(\ce{ch_{2}cl_{2}}\\) \\(\circ\\) \\(\ce{bf_{3}}\\) \\(\circ\\) \\(\ce{nf_{3}}\\)

Explanation:

Step1: Analyze \( H_2O \)

\( H_2O \) has a bent molecular geometry. The electronegativity difference between O and H creates polar bonds, and the bent shape means the dipole moments do not cancel. So \( H_2O \) is polar.

Step2: Analyze \( CH_2Cl_2 \)

\( CH_2Cl_2 \) has a tetrahedral geometry, but the C - H and C - Cl bonds have different electronegativities. The dipole moments of the C - Cl bonds do not cancel with the C - H bonds, so it is polar.

Step3: Analyze \( BF_3 \)

\( BF_3 \) has a trigonal planar geometry. The B - F bonds are polar, but the symmetric trigonal planar shape causes the dipole moments of the three B - F bonds to cancel each other out. So \( BF_3 \) is non - polar.

Step4: Analyze \( NF_3 \)

\( NF_3 \) has a trigonal pyramidal geometry (similar to \( NH_3 \)). The N - F bonds are polar, and the trigonal pyramidal shape means the dipole moments do not cancel, so it is polar.

Answer:

\( BF_3 \) (the option with \( BF_3 \))