Properties of water Flashcards
What kind of bond does water have? and why
It is polar covalent bc oxygen has more electronegativity than hydrogen
H+
OH-
What is specific heat?
-what kind of specific heat does water have and what does that mean?
The amount of heat that must be absorbed or lost for 1 gram of substance to change its temp by 1 degree C
Water has a HIGH specific heat, so it takes more energy for the temp to change which is why we do not freeze when we go outside
Temperature represents what?
and what does the changes in temp mean?
The average kinetic energy of molecules
Higher temp= more kinetic energy
Lower temp= less kinetic energy
Describe the H-bonds in liquid water
Continuous formation of hydrogen bonds forming, breaking, and forming again
Describe the H-bonds in ice
As the temp goes down bc ice is cold, H-bond breakage slows down
Describe the H-bonds in Gas (water vaporization)
As temp gets hotter, H-bond breakage speeds up
When you go from ice to water is energy added or released?
Added
When you go from water to gas is energy added or removed?
Added
When you go from gas to water is energy added or removed?
Removed
When you go from water to ice is energy added or removed?
Removed
How does water freeze?
From top-down
Cohesion
Water molecules are attracted to other water molecules and stick to each other via hydrogen bonding
Adhesion
Water molecules are attracted to other polar molecules and stick to each other via hydrogen bonding
Surface tension
Measure of the attraction between molecules at the surface of the liquid
Solute
Substance that dissolves in liquid
Solvent
Liquid that substance dissolves in
Solution
When solute dissolves in solvent
Hydration shell
Water molecule’s attraction to a
substance, and the shielding of the
charged nature of that substance
by water molecules
Hydrophilic
“water-loving”
* Dissolves in water
* Often polar or ionic
Hydrophobic
- “water-fearing”
- Insoluble in water
- Nonpolar, no charge
Amphipathic def
and what do they form?
Have both hydrophobic and hydrophilic regions
Amphipathic molecules form micelles when placed into water
Chemical reactions occur when?
2 or more elements or compounds combine
* 1 compound breaks down into 2 or more molecules
* Electrons added to or removed from atom
What is pH?
scale used to describe the
concentration of H+ and OH-
What happens to pH when it is more acidic
pH goes down
What happens to pH when it is more basic
pH goes up
What do Buffers do?
Buffers help to maintain a constant
pH
* Buffers:
* Pair of substances that minimize pH fluctuations in the fluids of living
organisms
* Consist of:
* Acid and its related
base
Do ions and polar molecules dissolve readily in water?
yes
Anions are attracted to the H+
Cations are attracted to the OH-
Since Water can dissociate into ions, H can shift from one water molecule to another, leaving behind what?
Leaving behind a hydroxide ion
(OH-), and forming a hydronium
ion (H3O+)
If a strong acid is added to a buffer (a.k.a. a weak acid) what will happen to the pH
When a strong acid is added to a buffer (a weak acid), the weak base in the buffer reacts with the H+ from the strong acid to form the weak acid HA. The pH change is only slight
