unit 1 - chapter 3 (water) Flashcards
what is polar covalent bonding?
unequal sharing of electron pair (partial positive & negative)
what are the 4 properties of water?
cohesion of water molecules, moderation of temperature by water, ice floats, and water is the solution
what is cohesion?
water sticks to itself
what does cohesion cause?
surface temperature
what is adhesion?
water sticks to other things
what is heat?
total kinetic energy
what is temperature?
average kinetic energy
what is heat?
a form of energy
what is heat measured in?
calories or joules
what is specific heat?
amount of heat required to change temperature
what’s in the blank?
water changes temperature more _____ than other substances
slowly
what’s in the blank?
water requires a _____ input of energy to change temperature
greater
what kind of specific heat does water have and what does this mean?
high specific heat, it can moderate temperature very well
why does ice float?
it has a lower density than water
what is a solution?
a uniform mixture of 2 or more substances
what is a solvent?
the liquid dissolving reagent in a solution
what is a solute?
the dissolved reagent in a solution
why does salt dissolve well in water?
the Cl- anions and Na+ cations get surrounded by the water molecules and can’t join back unless the water disappears
what does hydrophilic mean?
substances that are attracted to water
what does hydrophobic mean?
substances that repel water
what type of substances are usually hydrophilic?
generally ionic or polar substances
what type of substances are usually hydrophobic?
non-polar and non-ionic substances (like oils)
what is molecular weight the sum of?
all atomic weights
what is molarity?
the # of moles of solute per liter
what is avagadro’s number?
6.02 x 10^23 particles in 1 mole of substance
what is an acidic pH?
0-7
what is a basic pH?
7-14
what is a neutral pH?
7
what’s in the blank?
_____ are more reactive than water
ions
what are compounds that contribute H+?
acids
what are compounds that contribute OH-?
bases
what does the pH scale measure?
the concentration of protons
is lower pH more acidic or more basic?
more acidic
what is the equation relating pH and pOH?
pH + pOH = 14
what are buffers?
they act as acids, bases, or both; buffers minimize changes in pH
what’s in the blank?
buffers are _____ ionizing
weakly
what is an important buffer in vertebrate blood?
bicarbonate
how do buffers minimize changes in pH?
they absorb protons
what is an example of an ecological effect of pH?
acid precipitation
