Learning Outcomes
i. Define polarity, hydrogen bonding, specific heat, heat of vaporization, cohesion, hydrophobic exclusion, ionization, and lower density of ice.
ii. Explain the importance of the properties of water to life.
i. Polarity: Water is a polar molecule, which means that it has a positive and negative end. The positive end of the water molecule is the hydrogen atoms, and the negative end is the oxygen atom. This is because oxygen is more electronegative than hydrogen, meaning that it attracts electrons more strongly.
ii. Hydrogen bonding: Hydrogen bonding is a weak chemical bond that forms between the hydrogen atom of one water molecule and the oxygen atom of another water molecule. Hydrogen bonds are responsible for many of the unique properties of water.
iii. High specific heat: Water has a high specific heat, which means that it takes a lot of energy to raise the temperature of water by 1 degree Celsius. This is because the hydrogen bonds between water molecules must be broken in order for the water to heat up.
iv. High heat of vaporization: Water has a high heat of vaporization, which means that it takes a lot of energy to vaporize water. This is also because the hydrogen bonds between water molecules must be broken in order for the water to vaporize.
v. Cohesion: Cohesion is the tendency of water molecules to stick together. This is due to the hydrogen bonds between water molecules. Cohesion is responsible for surface tension, which is the ability of water to form a film on surfaces.
vi. Hydrophobic exclusion: Hydrophobic exclusion is the tendency of water molecules to exclude hydrophobic molecules. Hydrophobic molecules are molecules that are not attracted to water. Hydrophobic exclusion is responsible for the formation of cell membranes and for the way that water droplets form.
vii. Iization: Water is a weak electrolyte, which means that it can ionize into hydrogen ions (H+) and hydroxide ions (OH-). Ionization is important for many biological processes, such as metabolism and cell signaling.
viii. Lower density of ice: Water has a lower density in its solid state (ice) than in its liquid state. This is because the hydrogen bonds between water molecules in ice form a lattice structure that is less dense than the structure of liquid water.
Importance of the properties of water to life
The properties of water are essential for life. Polarity and hydrogen bonding allow water to dissolve a wide variety of substances, which is essential for metabolism and other cellular processes. High specific heat and heat of vaporization help to regulate body temperature. Cohesion and hydrophobic exclusion are important for the formation of cell membranes and other structures. Ionization is important for many biological processes, such as metabolism and cell signaling. The lower density of ice helps to prevent lakes and ponds from freezing solid, which would kill the organisms that live in them.
Real-world applications of the properties of water
The properties of water are used in a variety of products and industries. For example, the high specific heat of water is used in cooling systems, such as the radiator in a car. The high heat of vaporization of water is used in power plants to generate electricity. The cohesion of water is used in capillary action, which is the way that water moves up plants. Hydrophobic exclusion is used in the development of self-cleaning surfaces and water-resistant clothing. Ionization of water is used in water purification systems. The lower density of ice is used in the design of icebreakers and ice skates.
Water has many unique properties that make it essential for life. These properties include high polarity, hydrogen bonding, high specific heat, high heat of vaporization, cohesion, hydrophobic exclusion, ionization, and lower density of ice.
