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

Investigating Stoichiometry - The table shows the mass of reactants potassium iodide and lead(II) nitrate, and the mass of the precipitate from the reaction

Extracts from this document...


SSIS DP IB Program Science Investigation Report Investigating Stoichiometry Name: Kimberly Hoong Yearn Yi Class: H1Ruby Results Quantitative Data: The table shows the mass of reactants potassium iodide and lead(II) nitrate, and the mass of the precipitate from the reaction between KI(aq) and Pb(NO3)2(aq). Mass of precipitate from reaction between KI(aq) and Pb(NO3)2(aq) Mass of potassium iodide (�0.001g) 1.701 Mass of lead(II) nitrate (�0.001g) 1.280 Mass of filter paper (�0.001g) 0.798 Mass of precipitate + filter paper (�0.001g) 2.525 Mass of precipitate (�0.001g) 1.727 Qualitative Data: 1) After pouring the KI(aq) and Pb(NO3)2(aq) solution together into the beaker, a glass rod was used to stir the solution so as to make sure it was mixed properly. However, after stirring, when the glass rod was taken out, there were small amounts of precipitate (PbI2(s)) stuck onto the glass rod, and could not be removed. 2) While pouring the remaining mixture into the filter paper, not all the mixture was poured into the filter funnel and paper. ...read more.


Second, we predict the mass of PbI2 formed. Mass of PbI2 = 0.0038646176mol PbI2 x = 1.781550067g PbI2 � 1.782g PbI2 Step 2) Now we calculate the actual mass of PbI2 formed. Mass of filter paper = 0.798g Mass of precipitate (PbI2) + filter paper = 2.525g Mass of PbI2 produced = 2.525g - 0.798g = 1.727g Step 3) Now we calculate the percent yield. Percent yield of PbI2 = PbI2 x 100% = 96.91358025% � 96.9% Analysis of Results After conducting the experiment, it is found that the percent yield of PbI2 produced was 96.9%, which was rather accurate. However, it was lower than the predicted mass by 3.1%, which could be due to the qualitative results shown above, random errors and inaccuracy of the experiment. When stirring the KI(aq) and Pb(NO3)2(aq) solution, some of the PbI2 precipitate was stuck onto the glass rod used for stirring, and could not be removed without using fingers, which would have contaminated the solution. This resulted in the decrease in the actual mass of PbI2 precipitate measured, causing the percent yield to be slightly lower than the predicted yield. ...read more.


Limitations and Improvements If I could do the experiment again, --> As some of the precipitate was stuck onto the glass rod and could not be removed by using my fingers, I could have just used a little bit of water to wash it down back into the mixture. This would have decrease the difference in the percentage between the predicted yield and the percentage yield. --> Even though water was used to wash some of the mixture into the filter funnel, there was still some mixture stuck in the beaker. The process of using water to wash down the mixture could have been repeated over and over until all the mixture is in the filter funnel. --> After filtrating the mixture once, some of the PbI2 crystals went through the filter paper and into the filtrate in the conical flask. To make sure all the PbI2 precipitate is counted towards the percent yield, the filtrate could have been filtrated again at least 2 more times. This would have increased the mass of PbI2, which would have made the percent yield closer to 100%. ?? ?? ?? ?? 1 | Page Science Investigation - Stoichiometry ...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. Chemistry Lab Report Stoichiometry

    Hence when we began heating the copper sulphate hydrate, the leftover substance burned and our sample which was supposed to be turning white instead turned a little grey, because of the ashes.

  2. Can one determine the coefficients of a balanced chemical equation by having the mass ...

    Solid copper(ii) chloride will not react with aluminum because the intermolecular forces of the compound are too strong to be able to undergo the displacement that the reaction entails. This is why the copper(ii) chloride needs to be in a solution.

  1. Limiting Reagent Lab. Purpose To ...

    * The clear liquid was odorless like water. Analysis Reactants Mass ( � 0.10g) Potassium iodide (KI) 0.80 Lead (II) nitrate (Pb(NO3)2) 1.10 Table 2: Mass of reactants Theoretical value (g) Experimental value ( � 0.10g) Percent yield (%) Percent error (%)

  2. Potassium Iodide Lab

    With the pipettes, there could have easily been bubbles. The bubbles would take up space where the liquid should be for precise measuring. If twisted the wrong way, it would be easy for air to get trapped and cause these pockets.

  1. Percent Yield of a Precipitate

    Errors in this experiment may have been due to the fact that not all of the water had evaporated from the CaCO3 precipitate giving it a greater mass. Also, a paper filter by itself was used to drain out the water from the precipitate as opposed to a buchner funnel, so that not all of the water was drained out.

  2. Chemistry Internal Assesment - Stoichiometry (measuring 'x' in salt)

    time the whole mass the mass of salt loss of mass before - 10:19 12,1+0,1g 2,0+0,1g x 10:26 11,5+0,1g 1,6+0,1g -0,4+0,1g 10:32 11,3+0,1g 1,2+0,1g -0,8+0,1g 10:38 11,3+0,1g 1,2+0,1g -0,8+0,1g 10:44 11,3+0,1g 1,2+0,1g -0,8+0,1g Table 1: The procedure of losing salt's mass while heating during the first attempt.

  1. Percent Yield Lab. This experiment has proven that KI is the limiting reagent ...

    xPbI20.0120mol=1/2 X= 0.00602mol Theoretical Yield 0.00602*(461) = 2.78 g The limiting reagent should be KI. KI has the least amount of moles therefore you do not have enough to react with the excess Pb (NO3)2. Whereas PbI2has a higher amount of moles and will result to be the excess reagent.

  2. Research report on Stoichiometry

    Stoichiometry can be used to find quantities such as the amount of products (in mass, moles, volume, etc.) that can be produced with given reactants and percent yield (the percentage of the given reactant that is made into the product).

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