(Q3) GENCHEM: Lesson 3 The Structure and Unique Properties of Water

Step 1

Lewis Structure of the Water:

• _: Determine the number of valence electrons in

  each constituent element of the compound.

Step 2:

Lewis Structure of the Water:

• _: Determine the total number of valence electrons

  present in the covalent compound. This is the simply

  sum of all valence electrons present in each constituent

  element.

Step 3

Lewis Structure of the Water:

• _: Draw the skeleton structure of the molecule.

Step 4

Lewis Structure of the Water:

• _: Distribute the valence electrons to form the Lewis

  structure

Step 5

Lewis Structure of the Water:

• _ : If the valence electrons seem to be deficient to satisfy the octet rule for each element, multiple bonds can be drawn to satisfy the rule. In this compound, all atoms follow the octet rule.

Molecular geometry

• refers to the three-dimensional arrangement of atoms in a molecule.

• It describes the molecule’s shape, which depends on:

  • Number of bonding pairs of electrons

  • Number of lone pairs around the central atom

  • Repulsions between electron pairs

Step 1

Molecular Geometry of Water:

• _: Draw the Lewis structure.

Step 2

Molecular Geometry of Water:

• Count the total number of electron domains of the central

  atom.

Step 3

Molecular Geometry of Water:

• _: Identify the electron domain geometry of the molecule

Step 4

Molecular Geometry of Water:

• _: Identify the molecular group geometry and the bond angles between atoms in the molecule.

Four
Tetrahedral
Bent

• Water has _ electron domains around the central atom (0). It has two single bonds and two lone pairs. Its electron domain geometry is _, and its molecular geometry is _.

Hydrogen bonding
LDF
Dipole-dipole forces

Intermolecular Forces of Attraction: (H L D)

4.18 (j/g X C)

• Specific heat capacity (Liquid water)

2.11 (j/g X C)

• Specific heat capacity (Water vapor)

2.00 (j/g C)

• Specific heat capacity (Ice)

0 Celsius

• Melting point

100 C

• Boiling point

Water
Hydration spheres
Aggregate
Micelle

UNIVERSAL SOLVENT:

• _ is known to be the universal solvent due to

  its capacity to dissolve a wide variety of substances.

• _ when ionic compounds are

  dissolved in water, the ions break apart, and each

  ion will be surrounded by water molecules.

• There are molecules that contain both polar and non-polar groups.

• When Amphipathic molecules are placed in water they _ and form a structure called a _.

Heat capacity

• The amount of heat required to raise the

  temperature of a substance by one degree Celsius.

• Water has a high _ due to the strong

  intermolecular bonds.

• Extensive Property.

Specific Heat Capacity

• refers to the amount of heat required to raise the temperature of one gram of a substance by one degree Celsius.

• Intensive property

Density
Less
density

Phases of Water:

• _ is defined as the mass per unit volume

The more compact the particle arrangement is, the

higher the _ will be.

• When liquid water solidifies to ice, it arranges

itself based on the hydrogen bonding requirements.

• Ice is _ than water.