M3

• Definition of Terms:

  • Titrat: Refers to the substance that is being analyzed, also known as analyte or active constituent
  • Titrand: Known concentration used in the titration of titrant
  • indicator : a complex or organic substance that shows when the end point of a reaction has been reached by either formation of precipitate, evolution of gas, or a change in color
  • indicator: used to determine end points in neutralization processes and determine hydrogen-ion concentration or pH to indicate that the desired change in pH has been effected
• Titration:

  • Refers to the process of adding and measuring the volume of titrant used in the assay
  • It is a process whereby the standard solution is brought into the reaction
• Volumetric Analysis (Titrimetric Analysis):

  • A process where the volume of a solution of known concentration is used to determine the amount of an active constituent present in a sample
• Standardization:

  • The process where the exact concentration or value of a solution for a specific reaction is determined
  • Standard solution: a solution with a concentration of a high degree of accuracy, it is the product of standardization
• Chemical Reactions:

  • Law of Mass Action: the speed of a reaction is proportional to the products of the molecular concentrations of the reacting substances
  • Solubility Product Principle: the product of the concentration of the constituent ions in a saturated solution of a difficulty soluble salt for any given temperature is practically a constant
• Stoichiometric Point (Equivalence Point):

  • Otherwise known as equivalence point, refers to the theoretical point at which equal amounts of analyte and titrant have reacted
  • Normality: a concentration expression defined as the number of equivalents of solute per liter (eq) or milliequivalents per milliliter (meq/mL)
• End Point:

  • Also known as visual end point or experimental end point, this refers to the time at which the titration should be stopped and may be indicated by a sudden change in property of the mixture, it may be determined by the use of an indicator
  • Molarity: an expression of the concentration of a solution in terms of moles per liter (mol/L)
• Gravimetric Analysis:

  • The measurement of the weight of a substance in a sample or calculation of the weight of a substance in a sample from the weight of a chemically equivalent amount of some other substances using the general reaction formula
• Reduction-Oxidation Reaction:

  • A quantitative procedure in chemical reactions
• Gram Equivalent Weight:

  • It is the weight in grams of a chemical which is equivalent to 1 gram-atom of hydrogen
• Solution of AgCl contains 1.76 x 10^-3 g per liter
• Molecular weight of AgCl is 143.32
• In terms of molarity, the solution contains 1.23 x 10^5 mol/L of AgCl
• Silver chloride is slightly soluble in water, with a solubility of about 0.00001 mole (1.5 mg) per liter
• When the solubility of AgCl is exceeded, a precipitate of AgCl forms in equilibrium with the dissolved silver chloride
• The solubility product principle states that if the product of the concentrations of any pair of ions in solution exceeds the solubility product of the compound formed by their union, precipitation will occur
• If the product of the ionic concentrations is made less than the solubility value, the compound formed by their union will dissolve until the product of the ionic concentrations is equal to the solubility product value
• Common ion effect: Adding a common ion decreases solubility, causing precipitation as the equilibrium shifts towards the reactants
• Gravimetric analysis involves purifying a sample and weighing it without chemical change
• Chemical method in gravimetric analysis involves converting the substance to a chemically equivalent amount of another substance that can be separated
• Assay of NaCl involves calculating the % purity of the sample or the weight of chlorine present
• To calculate the quantity of chlorine present as chloride in the sample, the gravimetric factor is employed