Quiz 1 - Properties of Water Flashcards
(13 cards)
What is the structure of water?
Two hydrogen atoms and one oxygen atom connected through covalent bonds
What is polarity?
Electrons are unevenly distributed
Electrons are more attracted to oxygen, meaning they spend more time near oxygen giving water a slightly negative charge
What does polarity mean for water molecules?
Unequal sharing of electrons, meaning positive and negative poles, key to water’s unique property.
Occurs from the difference in electro-negativity
What is hydrogen bonding / cohesion?
The attraction between one water molecule to the next due to the possible hydrogen bonds.
1 H2O molecule can hydrogen bond with 4 others
What is adhesion?
The attraction of water to other substances like glass.
Water can hydrogen bond with other molecules other than water creating meniscus and capillary action.
What is specific heat capacity?
The amount of energy needed to raise the temperature of a unit mass of a substance 1 degree
Takes a lot of energy to heat up water (4.18 J/g (Degrees Celsius))
This is due to its numerous hydrogen bonds
What happens to water during the specific heat capacity?
Hydrogen bonds are broken to allow water to move freely and therefore become a gas
When water is cooled hydrogen bonds are reformed and release a large amount of extra energy
What is high heat of vaporization?
Water in it’s liquid form has an unusually high boiling point (100 degrees Celsius)
As water evaporates thermal energy is taken up by the process cooling the surface
Summarize the properties of water.
Polar - Water has a slight negative charge due to it’s distinguishable poles
Cohesive - Water molecules stick to each other
Adhesion - Water molecules stick to other surfaces
Resistant to temperature changes - Water has a high heat capacity
Coolant - Due to it’s energy and heat properties it makes a good coolant
What are hydrophilic and hydrophobic interactions?
Hydrophilic - Electrostatic interactions with water molecules due to attraction and polarization
Hydrophobic - The repulsion of water by non polar substances / molecules
How does surface tension force the surface of water to curve?
Due to it’s tendency to reduce the surface area of water.
How does capillary action work?
Adhesion to the walls of a vessel will cause an upward force in the water therefore moving the liquid upwards.
Why can water dissolve many substances?
Because of the polarization of water (positive and negative charge) it opens the possibilities allowing the water molecule to be attracted to many other molecules.
