Water Flashcards
High melting point, boiling point, and heat of vaporization
Special characteristics of water
H-O-H tetrahedral bond angle is what?
104.5 degrees
The result of the unequal electron sharing in water
A polar molecule
A bond between an oxygen atom of one water molecule and the hydrogen bond of another. Hydrogen can bond with FON
Hydrogen bond
Why are hydrogen bonds responsible for the high melting point of water?
So much thermal energy is required to break a large enough portion of hydrogen bonds to cause the crystal lattice of ice to melt.
Strong hydrogen bonds are is which, a straight line or an L shape
A straight line
Compounds that dissolve easily in water
Hydrophilic
Compounds that are not easily dissolved in water
Hydrophobic
Why is there an increase in entropy when a salt is dissolved in water?
Ions of the salt separate which provides a lot more freedom of motion compared to ions in a lattice. The freedom creates disorder which increases entropy
Does dissolving hydrophobic compounds increase or decrease entropy of water
Decreases entropy because water molecules are forced to become a ‘cage’ around non-polar molecules. Creates less disorder
Compounds that contain regions of polar and non-polar
Amphipathic
Stable structures of amphipathic compounds in water.
Micelles
Forces that hold non-polar regions of molecules together. Due to the system minimizing the number of water molecules that interact with the non-polar compound, NOT attraction between non-polar regions
Hydrophobic interactions
When two uncharged atoms are close together and their electron clouds influence each other. Brings the two nuclei close together
van der Waals interactions
Vapor pressure, boiling point, melting point, osmotic pressure. Comes from the fact that the concentration of water is lower in solutions than in pure water
Colligative properties
Water moves from a region of _ concentration to _ concentration
High concentration to low concentration
Water movement across a semipermeable membrane driven by differences in osmotic pressure
Osmosis
Solutions of osmolarity equal to that of a cell’s cytosol
Isotonic
Solutions with higher osmolarity than that of the cytosol. Water moves out of the cell
Hypertonic
Solution with lower osmolarity than the cytosol. Water moves into the cell
Hypotonic
When a cell bursts because of too much water pressure
Osmotic lysis
When blood plasma pH falls below 7.4
Acidosis
When blood plasma gets higher than 7.4
Alkalosis
Aqueous solutions that resist change in pH when small amounts of acid or base are added
Buffers
Flat zone where a given amount of acid or base added to the system has much less effect on pH than the same amount added outside of that zone
Buffering region
Reaction where elements of water are eliminated
Condensation reaction
Reaction when elements of water are added
Hydrolysis reaction
High specific heat of water is useful because
It allows water to act as a ‘heat buffer’ which keeps an organism’s temperature constant despite surrounding heat fluctuations
Ice being less dense than liquid water is important because
It keeps large frozen bodies of water from sinking to the bottom, killing all organisms beneath it