15.1 Precipitation and Dissolution

15.1 Precipitation and Dissolution

  • The preservation of medical laboratory blood samples, mining of sea water for magnesium, formulating over-the-counter medicines, and treating the presence of hard water in your home's water supply are just a few of the many tasks that involve controlling.
  • We want to prevent dissolution from happening.
    • The formula Ca5(PO4)3(OH) in our teeth can cause tooth decay.
    • The dissolution process is aided when the sugars in our diet are feasted on by the organisms in our mouths.
    • The decay is prevented by preventing the dissolution.
    • Sometimes we want a substance to break down.
  • In this section, we will learn how we can control the dissolution of a slightly ionic solid by applying Le Chatelier's principle.
    • We will learn how to use the equilibrium constant of the reaction to determine the concentration of ion present in a solution.
  • Silver chloride is a ionic solid.
    • In an earlier chapter, it was noted that halides of Ag+ are not normallysoluble.
  • The equilibrium is dynamic, but at the same time, Ag+ and Cl- ion in the solution combine to produce an equal amount of the solid.
    • The opposing processes have the same rates.
  • There is silver chloride.
    • When it is added to water, it creates a mixture consisting of a very dilute solution of Ag+ and Cl- ion in equilibrium with silver chloride.
  • In the chapter on solutions and colloids, we use an ion's concentration as an approximation of its activity in a dilute solution.
  • When looking at dissolution reactions such as this, the solid is listed as a reactant, whereas the ion are listed as products.
    • The product of the concentrations of each of the ion is written as the equilibrium constant expression.
    • When a solution of silver chloride is in equilibrium with undissolved Agsolved, the product constant is equal to Ag+ and Cl-.

  • The chapter began with an informal discussion of how the mineral is formed.

  • The constant of the copper(I) bromide's solubility product is 6.3.

  • The constant of calcium hydroxide's solubility is 1.3 x 10-6.

  • It is not always given as a molar value.
    • We need to convert the compound's solubility into moles per liter in order to use it in the constant expression of the product.
  • Artists use oil-based paints with a lot of the pigments that are in water.
    • The artist's chrome yellow, PbCrO4, has a solubility of 4.5 x 10 g/L.
    • The equilibrium product is PbCrO4.
  • The oil paints have a small amount of water in them.
    • Examples include chrome yellow (PbCrO4), red vermilion (HgS), and green color veridian.
  • The amount of PbCrO4 in grams per liter is given to us.
  • When thallium is being isolated from ores, the solubility of TlCl is 3.46 grams per liter.
  • The compound is composed of the diatomic ion of mercury, Hg2 and chloride.
    • calomel was used as a medication in the 18th century.
  • The molar solubility of Hg2 is calculated.
  • Determine the direction of change.
  • Hg2Cl2 is not in the calculation because it is a pure solid.
  • Check the work.

  • A variety of techniques are used to aid diagnoses of illnesses.
  • The ingestion of a barium compound is used to take an X-ray image.
    • The patient takes a suspension of barium sulfate.
    • Barium-coated areas of the digestive tract appear on an X-ray as white, allowing for greater visual detail than a traditional X-ray.
  • The suspension of barium sulfate coats the ile, which allows for more detail than a traditional X-ray.
  • Diagnostic testing can be done with barium sulfate.
    • A continuous Xray is passed through the body so the doctor can watch the barium sulfate's movement on a TV or computer screen.
    • In addition to acid reflux disease, barium sulfate can be used to diagnose other conditions.
  • Visit this website to learn more about how barium is used in medical diagnoses and which conditions it is used to diagnose.
  • A saturated solution with an undissolved solid will result.

  • When we mix equal volumes of AgNO3 and NaCl solutions, each concentration is reduced to half its initial value.

  • We can calculate the concentration that the other ion must exceed for precipitation to begin if we know the concentration of one ion and the value for the solubility product of the solid.
    • We will assume that precipitation begins when the reaction quotient is equal to the product constant.
  • If calcium is removed from the blood, it won't clot.
  • Adding anticoagulants to the blood will prevent the blood from clotting.
  • CaC2O4 isn't in this expression because it is a solid.
    • Water doesn't show up because it's the solvent.
  • Adding the solid silver nitrate will not increase volume.
  • It's useful to know the concentration of an ion after precipitation.
    • The concentrations are different because we are calculating them after the precipitation is over.

  • The pH is calculated from that.
  • The precipitation of Mg(OH)2 from sea water is the first step in the preparation of magnesium metal.
  • Due to their light sensitivity, silver halides are used in fiber optics for medical lasers, photochromic eyeglasses and photographic film before the advent of digital photography.
    • A solution of Ag+ and a solution of Cl-, Br-, and I- can be slowly added to a mixture of the solids.
  • Wastewater treatment facilities that may treat the municipal water in your city or town can use suibility equilibria.
    • It is possible to remove pollutants from wastewater before it is released back into the water.
  • The amount of oxygen available for marine life as well as making water unsuitable for human consumption can be impacted by an abundance of phosphate.
  • Wastewater treatment facilities remove pollutants before the water is released back into the environment.
  • Adding calcium hydroxide, known as Ca(OH)2, is one way to removephosphates from water.
    • calcium carbonate is a strong base in the water and is converted into lime.
    • Iron(III) chloride and aluminum sulfate can be used to removephosphates from precipitation.
  • There is more information on how to remove phosphorus from wastewater on this site.
  • In qualitative analysis, precipitation can be used.
    • Reagents are added to a chemical mixture in order to cause precipitation.
    • The addition of a reagent can be used to determine if the ion is present in the solution.
  • A solution has 0.10mol of KCl per liter.
    • Gradually AgNO3 is added to the solution.

  • We should find the concentration at which AgI begins to occur and the concentration at which Ag+ begins to occur.
    • The lower salt forms first.
  • AgI begins to form at a lower Ag+ than AgCl.
  • When we talked about buffer solutions, we noticed that the hydronium ion concentration of the solution of acetic acid decreased when the strong electrolyte Na CH3CO2 was added.
    • The effect can be explained using Le Chatelier's principle.
    • The equilibrium shifts to the left when the concentration of H3O+ is decreased to compensate for the increased acetate ion concentration.
  • The common ion effect can have a direct effect on equilibria.
    • When a change is made to a system at equilibrium, the reaction will shift to counteract it.
    • The reaction would shift to the left if there was an excess of iodide ion.