Ch.2 Physical properties of solution

• A solution is a homogenous mixture of two or more substances that are uniformly distributed

  
• Solute is the dissolved substance in a solution
• Solvent is the dissolving medium in a solution
• Dilute solution has a low concentration of solute in a given amount of solvent
• Saturated solution has the maximum amount of solute dissolved in a given amount of solvent
• Supersaturated solution has more than the maximum amount of solute dissolved in a given amount of solvent
• Hypotonic solution has a higher concentration inside the cell than outside, causing the cell to burst
• Isotonic solution has an equal concentration inside and outside the cell, balancing the movement of water in and out
• Hypertonic solution has a higher concentration outside the cell than inside, causing the cell to shrink
• Factors affecting the rate of dissolving:

  • Stirring/agitation moves the solute particles faster, speeding up dissolution
  • Heating gives solvent particles more kinetic energy, increasing collision rates
  • Powdering increases the surface area of solute in contact with the solvent
• Solubility is the amount of solute dissolved in a given amount of solvent
• Factors affecting solubility:

  • Nature of solute: "like dissolves like"
  • Temperature: solubility is directly proportional to temperature in solid and liquid, inversely proportional in gas
  • Pressure: minimal effect on solid and liquid solubility, significant effect on gas solubility
• Henry's Law states that the solubility of a gas in a liquid is directly proportional to the pressure exerted by the gas on the liquid's surface
• Common methods of expressing concentration of a solution include percent by mass, volume, mole fraction, molality, molarity, normality, and parts per million (ppm)
• TONICITY

  The concentration in and out of the cell membrane must be at

  equilibrium to ensure the normal functioning of the cells
• “KHEMEIA”

  art of changing inexpensive metals into expensive ones

  started in 1773

  Alchemy originated from the Greek word khemeia
• “KĒME”

  Chemistry came from the Egyptian word kēme, meaning “earth”

  Concerned with the composition, structure, and properties of matter,

  and its changes during chemical reactions
• B. PRESENCE OF SOLUTE IN AND OUT OF A CELL MEMBRANE

  • HYPOTONIC SOLUTION
  • ISOTONIC SOLUTION
  • HYPERTONIC SOLUTION
• Hyperbaric - high atmospheric pressure treatment
• CONCENTRATION

  The amount of substance divided by the total volume of a mixture
• COMMON METHODS OF EXPRESSING CONCENTRATION OF A SOLUTION

  a. Percent by

  · Mass

  · Volume

  · Mass/volume

  b. Mole fraction

  c. Molality

  d. Molarity

  e. Normality

  f. Parts per million (ppm)
• solution = msolute + msolvent
• Percent by mass$\frac{mass solute}{mass solution} *$$100$
• percent by volume$\frac{volume solute}{volume solution}*$$100$
• volume of solution = Vsolute + Vsolvent
• percent by mass/volume=$\frac{masssolute(g)}{volume solution(ml)} \times 100$
• mole fraction=$\frac{mole solute}{mole solution}$
• where mole, n=$\frac{mass}{molecularmass}$
• Molality (m)=$\frac{moles\;of\;solute}{kilograms\;of\;solvent}$
• Molarity (m)=$\frac{moles\;of\;substance}{volume\;of\;solution\;in\;Liters}$
• normality (n)=$M\times total\;positive\;oxidation\;number\;of\;solute$
• PARTS PER MILLION (ppm)

  Usually used to express the concentration of pollutants

  in the air, water, and soil.
• Parts per million (ppm)=$\frac{mass\;solute\;in\;mg}{volume\;water\;in\;liters} \;\;\;\frac{mass\;solute\;in\;mg}{mass\;soil\;in\;kilograms}$