Campbell Chapter 3
nature of the water molecule and the significance of hydrophilic and hydrophobic interactions
Terms
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- Diffusion of temperature
- when two objects are different they will become similar by diffusing KE
- pH scale
- scale from 0 to 14 to reflect hydrogen ion concentration in solution ph1 = 10-1 H ions (strong acid)
- Evaporative cooling
- most mobile molecules leave (hottest), leaving behind slower, cooler ones
- Heat
- total quantity of kinetic energy due to molecular motion
- Water's boiling point
- 100 degrees C
- Room temperature
- 20-25 degrees C
- Heat of vaporation
- quantity of heat a liquid must absorb for 1 g to be converted from liquid to gas- water = 580 cal
- Solvent
- substance which is dissolving agent- (in an aqueous solution = water)
- hydrophilic
- water loving- polar or ionic, water clings to compound but does not dissolve
- Buffers
- substances that minimize changes in concentration of H and OH by containing weak acid and weak base which donate electrons
- kilocalorie
- amount of heat needed to raise or lower one kilogram of water one degree
- Avagadro's number
- 6.02 x 10(23)= numbers of molecules in a mol
- water's specific heat
- 1 calorie; high because of its hydrogen bonds, needs to break or reform; changes temperature less when it absorbs or loses given amount of heat
- Temperature
- inensity of heat due to average KE
- pH
- = -log[H+] change is by 10 for every one unit; [OH][H] = 10(-14)
- Ice
- water forms less dense crystalline lattice b/c hydrogen bonds keep space between molecules
- polarity of water
- has polar covalent bonds; H is partially positive, O is partially negative
- cohesion
- H bonds hold water together, change partners constantly
- hydration shell
- sphere of water molecules around each ion
- Molarity
- number of moles of solute per liter of solution
- molecular weight
- sum of all the weights of all atoms in a molecule
- Solute
- Substance being dissolved (sugar, kool aid,...)
- Dissociation of water
- H2O <=> H+ + OH- + H20 <=> OH- + H3O+
- Temperature of the human body
- 37 degrees C
- mole
- number of molecular weight of substance in grams
- Temperature of water's greatest density
- 4 degrees C
- Acid
- substance that increases the hydrogen ion concentration (HCL -> H + Cl)
- adhesion
- clinging of one substance to another
- hydrophobic
- non ionic and non-polar; repels water
- Solution
- homogeneous mixture of two or more substances
- Types of molecules dissolvable in water
- polar and/or ionic Na+....HOH....Cl-
- calorie
- the amount of heat needed to raise or lower one gram of water one degree C= 4.1845
- specific heat
- the amount of heat that must be absorbed or lost for 1 g of a substance to change temp 1 degree C; how well a substance can resist change
- Water freezing point
- 0 degrees C
- Kinetic energy
- how fast something is moving
- surface tension
- measure of how dificult it is to stretch or break the surface of a liquid
- joule
- 0.239 calories
- Base
- substance that reduces the hydrogen ion concentration; accepts free H ions or releases OH ions (NH3 <=> NH4+) or (NaOH -> Na+ + OH-)