Question

If the symbol X represents a central atom, Y represents outer atoms, and Z represents lone pairs on the central atom, the structure Y---X---Y (2 lone pairs around X) could be abbreviated as XY2Z2. Classify these structures according to their shape.Molecular Geometries: linearbent 120bent 109trigonal pyramidalT-shapedsee sawsquare planarsquare pyramidalPossiblities:XY4Z2XY5ZXY2ZXY2Z3XY4ZXY2Z2XY3Z2XY3Z

Answer 1

Answer:

XY₄Z₂: square planar

XY₅Z: square pyramidal

XY₂Z: bent 120

XY₂Z₃: linear

XY₄Z: seesaw

XY₂Z₂: bent 109

XY₃Z₂: T-shaped

XY₃Z: trigonal pyramidal

Explanation:

According to the VESPR theory, the molecular geometry depends on the repulsion of the pairs of electrons of the valence shell.

Let

• X: central atom

• Y: outer atom

• Z: lone pair

Classify these structures according to their shape.

• XY₄Z₂: This molecule has 4 + 2 = 6 electron domains so the corresponding electron geometry is octahedral. Given there are only 4 outer atoms, the molecular geometry is square planar.

• XY₅Z: This molecule has 5 + 1 = 6 electron domains so the corresponding electron geometry is octahedral. Given there are only 5 outer atoms, the molecular geometry is square pyramidal.

• XY₂Z: This molecule has 2 + 1 = 3 electron domains so the corresponding electron geometry is trigonal planar. Given there are only 2 outer atoms, the molecular geometry is bent 120.

• XY₂Z₃: This molecule has 2 + 3 = 5 electron domains so the corresponding electron geometry is trigonal bipyramidal. Given there are only 2 outer atoms, the molecular geometry is linear.

• XY₄Z: This molecule has 4 + 1 = 5 electron domains so the corresponding electron geometry is trigonal bipyramidal. Given there are only 4 outer atoms, the molecular geometry is seesaw.

• XY₂Z₂: This molecule has 2 + 2 = 4 electron domains so the corresponding electron geometry is tetrahedral. Given there are only 2 outer atoms, the molecular geometry is bent 109.

• XY₃Z₂: This molecule has 3 + 2 = 5 electron domains so the corresponding electron geometry is trigonal bipyramidal. Given there are only 3 outer atoms, the molecular geometry is T-shaped.

• XY₃Z: This molecule has 3 + 1 = 4 electron domains so the corresponding electron geometry is tetrahedral. Given there are only 3 outer atoms, the molecular geometry is trigonal pyramidal.