Properties of Water Flashcards
U1L2
What are the six properties of Water?
Cohesion/Adhesion
Lower Density Solid
High Specific Heat Capacity
High Heat of Vaporization
High Heat of Fusion
Solubility
Ionization
(Surface Tension is also here but briefly mentioned)
What is Cohesion/Adhesion?
Cohesion is the clinging of a substance to itself, The H-Bonds between the water molecules hold it together.
Adhesion is the clinging of a substance to another substance (like the meniscus observed when measuring water in a grad. cylinder).
Why is Cohesion/Adhesion important?
Cohesion between water molecules allows for new water molecules to be drawn up behind it by the Xylem in trees. This allows for the plant to be hydrated from the root up.
Adhesion between the cell walls of the plants
xylem and the water molecules allows for capillary action,
where water is drawn up.
What is a Low Density Solid?
Water is most dense at 4C.
Because of this, Ice is less dense than water.
Water is the only dense that becomes less dense as a solid.
Why is Water being a LDS (low density solid) important?
Its important in aquatic life because as the water cools below 0c, the water gradually solidifies into ice. The water below the ice remains at a steady 4C, which allows for aquatic life to survive (providing the creatures can sustain in temperatures like that).
What is High Specific Heat Capacity?
Specific Heat Capacity is the amount of energy required to heat 1g of a substance by 1C.
Water has a relatively High SHC.
Water is capable of absorbing a lot of heat without increasing in temperature.
What is the significance of specific heat capacity?
Animals are able to maintain a mostly constant body temperature because the water in their bodies act as a heatsink.
Large bodies of water have a moderating effect on land nearby.
What is High Heat of Vaporization/Fusion?
Vaporization: Energy needed to change water from a liquid to a gas
Fusion: A lot of energy required to change ice from a solid to a liquid.
What is the Biological significance of Vaporization/Fusion?
Sweat.
When a human sweats, it draws a large amount of heat from the body as the sweat evaporates, helping to cool down the body.
What is Solubility?
Water is Soluble due to it’s high polarity (from the Oxygen molecule). Because it is a Polar Molecule, it allows for it to dissolve substances in water.
Water forms a hydration shell.
Why is Solubility significant?
Because it allows for water to dissolve compounds such as salt, sugar and certain vitamins and minerals.
What is Ionization?
Ionization is rare and reversible.
H+ and OH- are very reactive and control the pH balance of the body.
