Biol 150- Chapter 3

How is water a polar molecule?

• opposite ends have opposite charges

• hydrogen bonds

• covalent bonds

what are four properties of water?

• cohesive behavior, ability to moderate temp, expansion upon freezing, versatility as a solvent

• can't freeze but has cohesive behavior, ability to moderate temp and is versatile as a solvent

• can freeze, can heat up, can melt, and evaporate

cohesion vs. adhesion

• adhesion holds water molecules together

• cohesion holds water molecules together

• adhesion attracts different substances

• cohesion attracts different substances

what is kinetic energy vs. heat vs. temp?

• they all have to do with heat and energy but one is more than the other

• energy in motion

• heat is the total amount of kinetic energy

• temperature measures the intensity of heat into the average kinetic energy of molecules

what is a calorie?

• amount of heat required to raise the temp of 1g of water

• found in food packages

• amount that is measured for h2o bonds

what is a kilocal?

• calories on food packages 1 kcal= 1000 cal

• the same thing as calories just more fancy

• a kilogram of calories

What is specific heat?

• amount of heat absorbed or lost for 1g of substance that changes by 1 celsius

• specified heat that can only be seen when changed by one celsius

• heat specific to the situation

what is evaporation/evaporative cooling/heat of evaporation?

• all have to do with liquid evaporating into different substances like steam, gas, poison

• liquid to gas

• the heat a liquid must absorb for 1g to be converted to gas

• when liquid evaporates the remaining surface cools

What is the benefit of evaporative cooling to life?

• it helps stabilize temperatures in organisms & bodies of water

• it helps us not feel so hot after sweating

• it helps with others live without fear of melting into the earth

how does ice float & what would happen if it didn't on earth?

• humans would die and only animals would survive

• Because of hydrogen bonds and ice is less dense than H2O

• everybody would freeze leaving earth inhabitable

• because of nonpolar bonds