Question

question 1
which compounds will have dipole - dipole iaf.
you will need to draw the lewis diagram.
so₂
sio₂
ch₂f₂
c₂h₆

Explanation:

Step1: Analyze \(SO_2\)

• Lewis structure: S is the central atom. S has 6 valence electrons. Each O has 6 valence electrons. The structure is \(O = S - O\) with a lone pair on S.
• Molecular geometry: Bent. Since there is an electronegativity difference (\(O > S\)) and the molecule is polar, it has dipole - dipole interactions.

Step2: Analyze \(SiO_2\)

• Lewis structure: It has a network covalent structure (not a simple molecular structure). In the context of intermolecular forces (which are relevant for molecular substances), \(SiO_2\) (quartz, a covalent network solid) does not have dipole - dipole forces. The forces in \(SiO_2\) are covalent bonds within the network.

Step3: Analyze \(CH_2F_2\)

• Lewis structure: C is the central atom. C has 4 valence electrons, each H has 1, and each F has 7. The structure is \(H - C - H\) with two \(C - F\) bonds.
• Molecular geometry: Tetrahedral (but polar because \(F\) is more electronegative than \(C\) and \(H\)). Since it is a polar molecule, it has dipole - dipole interactions.

Step4: Analyze \(C_2H_6\)

• Lewis structure: \(H - C - C - H\) with all \(C - H\) and \(C - C\) bonds.
• Molecular geometry: The \(C - C\) bond is non - polar and \(C - H\) bonds have a very small electronegativity difference. The molecule is non - polar (symmetrical in terms of charge distribution). So, it does not have dipole - dipole interactions (has London dispersion forces instead).

Answer:

\(SO_2\), \(CH_2F_2\)