GEN CHEM 4TH QUARTER

• it refers to the transformations of matter from one state to another, such as from solid to liquid, from liquid to gas, and vice versa

  phase changes
• phase changes - refers to the transformation of matter from one state to another
• melting - phase change from solid to a liquid
• it is the phase change that occurs when a substance is heated, its particles gain enough energy to overcome the attractive forces holding them in a solid arrangement

  melting
• freezing - phase change from a liquid to a solid
• it is the phase change that occurs when a substance is cooled, its particles lose energy, reducing their movement and causing them to arrange into a more ordered solid structure

  freezing
• vaporization - phase change from a liquid to a gas.
• it is the phase change that occurs when a substance is boiled (the entire substance reaches its boiling point and turns into a gas) or through evaporation (only the surface molecules of a liquid gain enough energy to escape into the gas phase)

  vaporization
• condensation - phase change from a gas to a liquid
• it is the phase change that occurs when a gas loses enough energy to slow down and come together to form a liquid

  condensation
• sublimation - phase change from a solid directly to a gas, without passing through the liquid phase
• it is a phase change that occurs when a substance gains enough energy to break free from the solid structure and enter the gas phase

  sublimation
• deposition - phase change from a gas directly to a solid without passing through the liquid phase
• it is a phase change that occurs when a gas loses enough energy to condense directly into a solid form

  deposition
• phase diagram - a graphical representation of the physical states of a substance under different conditions of temperature and pressure
• this diagram shows the boundaries between the different phase regions and the points at which phase change occurs

  phase diagram
• what are the three areas of a phase diagram?

  solid, liquid, and vapor
• what does the x-axis of a phase diagram represent?

  temperature
• what does the y-axis of a phase diagram represent?

  pressure
• what are the three features of a phase diagram?

  the three areas, the three lines (curves), and the two important points
• what does the green line in the phase diagram divide?


  solid and liquid phases
• what does the blue line in the phase diagram divide?

  liquid and gas phases
• what phases does the green line represent?

  melting and freezing points
• what does the blue line in the phase diagram represent?

  vaporization and condensation
• what are the two important points in the phase diagram?

  the triple point and the critical point
• what is the triple point in the phase diagram?

  a point where all three phases of matter are at equilibrium and the three states of matter coexist
• what is the critical point in the phase diagram?

  a point where a substance's liquid and gaseous phases merges into a single phase.
• what is the merged single phase in critical point called?

  supercritical fluid
• what does a heating curve show?

  the change in temperature of a substance as heat is added
• what does a cooling curve show?

  change in temperature as heat is removed
• in both the heating and cooling curves, what do plateaus or straight lines indicate?

  the substance is changing states rather than changing temperature
• the concentration of solution - the quantity of solute that is contained in a particular quantity of solvent
• solute - a substance that is dissolved in a solution
• solvent - a liquid that can dissolve other substances, such as water
• solution - a type of mixture involving two or more substances
• the ratio of the number of moles of one component of a mixture to the total number of moles of all components

  mole fraction (X)
• the number of moles of solute dissolved in one liter of solution

  molarity (M)
• the ratio of the number of moles of solute per kilogram of solvent


  molality (m)
• moles of component/total moles of all components

  mole fraction
• moles of solute (mol)/liters of solution (L)

  molarity (M)