Chapter 3 Flashcards
Cohesion
At any moment, all the water molecules are linked by multiple hydrogen bonds, these bonds make water highly structured
o Responsible for transport of water and dissolved nutrients against gravity of plants
Adhesion
the clinging of one substance to another
o Adhesion of water to molecules of cell walls helps counter the downward pull of gravity
surface tension
a measure of how difficult it is to stretch or break the surface of a liquid
o Neatly arranged water molecules are at the surface of water, separating it from air, giving water an unusually high surface tension
o Ex: Overfilling a glass of water, water will stand over the brim
kinetic energy
energy of motion
o The faster a molecule moves, the greater its kinetic energy
thermal energy
-form of kinetic energy
the energy associated with the random movements of atoms or molecules
temperature
measure of the average kinetic energy of molecules in a body of water
heat
the thermal energy in transfer from one body of matter to another
calorie (2 defns)
amount of heat it takes to raise the temperature of 1 g of water by 1°C
• Also is the amount of heat 1 g of water releases when it cools by 1°C
Kilocalorie
(1000 cal), the quantity of heat required to raise the temp. of 1 kg of water by 1°C
Joule
one joule=.239 cal, 1 cal=4.184 J
specific heat
the amount of heat that must be absorbed or lost for 1 g of that substance to change its temperature by 1°C
o How well a substance resists change in its temperature when it absorbs or releases heat
• Specific heat of water: 1 cal/ g x °C
Heat of vaporization
the quantity of heat a liquid must absorb for 1 g of it to be converted from liquid to gaseous state
o Water has high heat of vap. To evaporate 1 g at 25°C, you need 580 cal heat (which is a lot of heat/energy).
Evaporative cooling
as liquid evaporates, the surface of the liquid remaining cools down
Solution
a liquid that is a completely homogenous mixture of two or more substances
Solvent
what does the dissolving
