BLG1501 - Chapter 03 2023 with verified questions and answers

cohesion phenomenon of a substance being held together by hydrogen bonds. adhesion attractions between different substances. surface tension measure of how difficult it is to stretch or break the surface of a liquid. kinetic energy the energy of motion. heat total kinetic energy due to molecular motion in a body of matter. temperature measure of heat intensity due to the average kinetic energy of molecules in a body of matter, regardless of volume. thermal energy reflects total kinetic energy and depends on volume. calorie amount of heat it takes to raise the temperature of 1g of water by 1 degree Celsius. specific heat amount of heat that must be absorbed or lost for 1g of a substance to change its temperature by 1 degree Celsius. specific heat of water 1 calorie per gram per degree Celsius. vaporization (evaporation) transformation from liquid to gas. heat of vaporization quantity of heat a liquid must absorb for 1g to be converted into the gaseous state. evaporative cooling cooling of a liquid's surface when a liquid evaporates. solution a liquid that is a completely homogenous mixture of 2 or more substances. solvent dissolving agent of a solution. solute substance dissolved in a solution. aqueous solution solution in which water is the solvent. hydration shell a sphere of water molecules surrounding an ion. hydrophilic substance that has an affinity for water. hydrophobic substance that does not have an affinity for water. molecular mass sum of all masses of all atoms in a molecule. mole amount of substance that has a mass in grams numerically equivalent to its molecular mass in Daltons, n=m/Mr. molarity number of moles per litre solution, M=n/L. Avogadro's number 6.02 x 10^23. acid substance that increases the H+ concentration of a solution. base substance that reduces the H+ concentration of a solution. pH scale scale used to measure the degree of acidity, ranges from 0 to 14. pH -log[H+]. buffer substance that minimizes large sudden changes in pH.