• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Potassium Iodide Lab

Extracts from this document...


Lindsay Zackeroff Mr. Mardulier/4 Chemistry Honors 2/27/08 I. Title: Finding the Formula for Lead Nitrate II. Purpose: This experiment was to test the different concentration levels of specified alkali metals to determine the greatest mass of lead nitrate. III. Background Information: Potassium Iodide Potassium Iodide is a crystallized, white salt but known to turn a bright yellow when exposed to prolonged moisture such as mixing with water. It is a simple iodine salt. In its natural state it is mostly colorless and odorless. If tasted, it would be like saline and extremely bitter and is has a relatively low level of hazard. Its main use is in photography but also used in table salt to "iodize" food and can be used in expectorants for lung congestion. It can also be used to protect the thyroid from radioactive iodine Potassium iodide IUPAC name Potassium iodide Other names Kalium iodide, knollide, potide Identifiers CAS number [7681-11-0] RTECS number TT2975000 Properties Molecular formula KI Molar mass 166.00 g/mol Lead Nitrate Lead Nitrate is a hazardous colorless crystal or white powder. It has a long history of uses. Until 1974, when the dangers of lead were realized, it was in a variety of products. Lead(II) nitrate IUPAC name Lead(II) nitrate Other names Lead nitrate Plumbous nitrate Lead dinitrate Plumb dulcis Identifiers CAS number [10099-74-8] RTECS number OG2100000 Properties Molecular formula Pb(NO3)2 ...read more.


e) cautions: One must ensure to Read the meniscus at the proper point Use a plastic graduated cylinder for elimination of meniscus Measure by getting down at eye level Carefully take proper measurements Use two filter papers for double filtration Zero the scale after first weighing the filter paper Use an electronic scale for accuracy Product enhancements to minimize error Digital scale Pipette's measurements to allow a few drops of solution to be retained Plastic graduated cylinders for no confusion figure 1: rinsing setup figure 2: Pipette dispensing of liquids figure 3: filtering apparatus VII. Analysis The lab performed was found to be an effective way of discerning the formulation of lead nitrate and potassium iodide's precipitate and use the chemical formula to understand the reaction. The formula is as follows: KI + Pb(NO3)2 --> PbI + K(NO3)2. Potassium Iodide and Lead Nitrate yield Lead Iodide and Potassium Nitrate. The reaction taking place is known to be a double replacement. The two compounds split and then combine with the counterparts. The PbI remains in the solution and the K(NO3)2 forms the precipitate. The purpose of the experiment was to find which combination of concentrations would consequently have the greatest impact on the mass of the Lead Iodide. It was found that when the concentrations of each are 5:5, the filtration leaves a substantial amount of the liquid and the yellow precipitate known as lead iodide is at the peak of the masses. ...read more.


Another space for error is the filter papers. Some of them were larger than the others. This can distort the results. The same filter paper should be used for all of those participating in the tests. The papers also varied in thickness. Others used only one paper, allowing too much precipitate through, and others used more than two. This allows the paper to absorb too much liquid instead of filtering it all the way through. An additional problem is evaporation. Leaving the filtration apparatus uncovered could allow gradual evaporation. Quite oppositely, the humidity in the room could also cause tampering with the solution. With the weather changes, the temperature of the lab was not held at a constant. One day it was heated the next was at a very cool temperature. This could easily have an effect on the experiment. All these reasons could have a great deal in the variety of results. The experiment would need to be performed again to accurately portray the data. Human error would need to be nonexistent VII. Conclusion As previously stated, the results of the experiment were not all in agreement. The different classes obtained various results. This can be due to human error. After realizing the effects on the reaction taking place, it was also discernable how concentration can easily affect the combination. However valuable knowledge on the formation of lead iodide was gained from this lab and the purpose was successfully completed. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our International Baccalaureate Chemistry section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related International Baccalaureate Chemistry essays

  1. Preparation and Composition of Tin (IV) Iodide

    0.1918g Total mass of product obtained/g (E1 + E2) 2.0850g Calculation of the % yield Mr of SnCl2.2H2O = 229.9350 Mr of SnCl2 = 189.616 Mass of SnCl2.2H2O weighed = 3.0020g Mass of SnCl2 in 3.0020g of SnCl2.2H2O = x 3.0020g = 2.4756g of SnCl2 Therefore, this mass (2.4756g)

  2. The purpose of this lab experiment is to determine whether different ionic compounds containing ...

    At the very end, use a pipette to get a precise measurement and get 10.0 mL 6. Close the ethanol (evaporates quickly) 7. Pour the ethanol from the graduated cylinder into the Erlenmeyer flask 8. Add in the ionic compound 9.

  1. Determination of potassium hydrogen carbonate into potassium carbonate

    The enthalpy for a reaction depends on the difference between the enthalpy of the products and the enthalpy of the reactants. It is independent on the route of which the reaction might occur on. Therefore the enthalpy change for a reaction is the sum of the individual enthalpy changes for each step.

  2. Limiting Reagent Lab. Purpose To ...

    ??� PbI2 ( s ) + 2KNO3(aq ) It can be presumed from the chemical formula of potassium iodide and lead (II) nitrate that double replacement reaction would occur, which produces lead (II) iodide and potassium nitrate. According to the solubility table - I is insoluble with and Pb2+ NO3 is soluble with all cations.

  1. rate of evaporation

    acid, H3PO4 0.024 � 12.74% Sulphuric acid, H2SO4 0.028 � 12.78% Table 4: rate of evaporation with uncertainties Graph 1 : rate of evaporation of different liquids LIMITATIONS AND SUGGESTIONS Limitation 1. The water loss is difficult to see when it is fully evaporate 2.

  2. An Experiment to Determine the Empirical Formula of Lead Iodide

    5) Each beaker was covered with a watch glass. 6) The mixture was gently heated on an iron stand with cartridge burner in the fume hood until all of the lead has dissolved or until steam exits from under the watch glass 7)

  1. IB Chemistry Lab Design - compare the effect of temperature on the concentrations of ...

    ascorbic acid from being oxidised, and thus their presence may lead to inaccurate results. Thus, they need to be eliminated. This can be done by using distilled water (without any salts) while preparing the solution of ascorbic acid. Head Space Present in System The ascorbic acid gets denatured because of oxidation by air.

  2. Biodiesel Investigation - How the concentration of Potassium Hydroxide solution would affect the yield ...

    is measured by an arbitrary percentage figure as well as a known uncertainty. Furthermore, the potassium hydroxide serves as a catalyst for the reaction. Equipment Used: Apparatus Uncertainty 10cm3 Measuring Cylinder 0.2ml Mass Balance 0.005g 50cm3 Beaker 5ml Magnetic Stirrer N/A Thermometer 0.5ºc Magnet Capsule N/A Method: 1.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work