Question

Sketch the shape of a linear triatomic molecule, a trigonal planar molecule containing four atoms, a tetrahedral molecule, a trigonal bipyramidal molecule, and an octahedral molecule. Give the bond angles in each case.

Short answer

A linear triatomic molecule has a \(180^{\circ}\) bonds angle, a trigonal planar molecule has a \(120^{\circ}\) bonds angle, a tetrahedral molecule has a \(109.5^{\circ}\) bonds angle, a trigonal bipyramidal molecule has \(90^{\circ}\) and \(120^{\circ}\) bond angles, while an octahedral molecule has a \(90^{\circ}\) bonds angle.

Step-by-step solution

Linear Triatomic molecule

A Linear triatomic molecule is a molecule that contains three atoms arranged in a straight line. The bond angle in such a molecule is, therefore, \( 180^{\circ} \). An example is carbon dioxide (CO2).

Trigonal Planar molecule

This has one atom in the center and three atoms at the corners of an equilateral triangle, all in one plane. The bond angle is \( 120^{\circ} \). For example, Boron Trifluoride (BF3).

Tetrahedral molecule

A tetrahedral molecule features one atom at the center and four others around it, located at the vertices of a tetrahedron. The bond angle between these atoms is \( 109.5^{\circ} \). Methane (CH4) is an example of a tetrahedral molecule.

Trigonal Bipyramidal molecule

This structure has five atoms. One atom is in the center, three atoms form an equilateral triangle in one plane, and the other two are above and below the center atom, forming a shape resembles two pyramids base-to-base. The bond angles occurring in this molecule are \( 120^{\circ} \) and \( 90^{\circ} \). One example is Phosphorus Pentafluoride(PF5).

Octahedral molecule

An Octahedral molecule consists of six atoms surrounding one atom in the center. The structure forms two square planes which are perpendicular to each other. The bond angles here are \( 90^{\circ} \). Sulfur hexafluoride (SF6) is one example.