Steric Number and Molecular Geometry

The video tutorial explains how to determine the steric number for water (H2O) by examining its Lewis structure. It details the process of counting atoms bonded to the central atom and lone pairs of electrons. The steric number is then used to deduce the molecular geometry of water, which is bent due to the presence of two lone pairs. The tutorial emphasizes the importance of steric number in understanding molecular shapes.

What is the first step in determining the steric number for a molecule like water?

• Identifying the molecular geometry

• Drawing a valid Lewis structure

• Calculating the molecular weight

• Counting the total number of atoms in the molecule

How many hydrogen atoms are bonded to the central oxygen atom in water?

• One

• Four

• Two

• Three

What is the steric number for water?

• Five

• Two

• Four

• Three

Why is the steric number important in chemistry?

• It predicts the boiling point

• It is used to find the molecular geometry

• It determines the color of the compound

• It helps in calculating the molecular weight

What molecular geometry does water have based on its steric number and lone pairs?

• Bent

• Trigonal planar

• Tetrahedral

• Linear

How many lone pairs are present on the central oxygen atom in water?

• One

• Four

• Two

• Three

What is the role of lone pairs in determining the molecular geometry of water?

• They make the molecule linear

• They contribute to the bent shape

• They increase the molecular weight

• They do not affect the geometry