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

Can one determine the coefficients of a balanced chemical equation by having the mass of a reagent, the mass of the dry product and by using stoichiometry?

Extracts from this document...

Introduction

Purpose Can one determine the coefficients of a balanced chemical equation by having the mass of a reagent, the mass of the dry product and by using stoichiometry? Hypothesis If the mass of the aluminum and the mass of the dry product, copper, is known then the balanced chemical equation can be derived by converting the masses to moles by dividing by the empirical molar masses of the elements, and then one can do a mole to mole ratio between this product and the reactant to make a balanced chemical equation. In a balanced chemical equation the coefficients of the chemical equation are indicative of the ratio of moles of the reactants and the products in a reaction. Since molar mass is also the mass per mole of substance and one knows the mass, then if one divides the mass determined from the experiment by the molar masses of each element then logically one will get the number of moles of the substance. From there a mole to mole ratio can be done between the product and the reactant and since a chemical equation can not have a fraction as a coefficient, then the coefficients can be multiplied on both sides by a number that will get a whole number for both elements. Since the law of conservation of mass states that anything that any quantity of substance that is put into the equation must result in the same quantity coming out of it and vice versa. This means that the very same mole to mole ratio can be applied to copper(ii) chloride and aluminum chloride to get the coefficients on those compounds. Hence finding the balanced chemical equation of the reaction. Procedure 1. Before the experiment is performed, two data tables are constructed. This is crucial because the time in the lab must be used efficiently, and time cannot be wasted in creating data tables which must be used for recording qualitative and quantitative observations. ...read more.

Middle

In addition spray the copper with water so that any aluminum chloride clinging to the filter paper gets washed down to the bottom. This better isolates the copper, ensuring precision within the experiment. 17. Take note of the qualitative observations of the copper after filtering out the aluminum chloride and solution. This is to ensure that copper truly is the dry product of the reaction. Record all these properties in "Data Table 1 - Qualitative Data Table" and record it under "After Reaction". 18. Lay the filter paper out to evaporate out the water on the copper so that the precision of the experiment is being up-kept. Note that one should only lay it out for approximately twenty-four hours so that the copper does not oxidize. If the copper does oxidize, the mass of the perceived copper would increase and the precision of the experiment would be ruined. 19. After twenty-four hours repeat step 3 and come back and determine the mass of the copper with the filter paper on the OHAUS Precision Standard Weighing balance. This mass will help isolate the mass of the copper in later calculations. Record this mass in "Data Table 2 - Quantitative Data Table" under "Mass of Copper with Filter Paper(�0.01g)". Sample Data Table 1 - Qualitative Data Table Time Qualitative Observations Before Reaction During Reaction After Reaction Sample Data Table 2 - Quantitative Data Table Masses Values Mass of Aluminum(�0.01g) Mass of Copper with Filter Paper(�0.01g) Mass of Filter Paper(�0.01g) Data Collection and Processing Data Table 1 - Qualitative Data Table Time Qualitative Observations Before Reaction � Copper(ii) chloride solution has a teal colour. � It is also liquid and translucent. � Aluminum is a gray, ductile, shiny, solid metal. During Reaction � Solution immediately turns into a very dark green colour with quite a lot of bubbling. � Overtime the part of the aluminum in contact with the solution turns a brick red colour. ...read more.

Conclusion

chloride should be the same as the mass of the copper in the dry product. In addition the the mass of the chlorine in Aluminum chloride should be the same as the mass of the chlorine in the copper(ii) chloride. Finally to find the mass of the aluminum can be found by finding the total mass of aluminum chloride by multiplying the mass of the chlorine by the reciprocal of the percentage of chlorine in aluminum chloride. Then to find the mass of the aluminum one would have to take the percentage composition of aluminum in aluminum chloride and multiply it by this total mass. This then gets the mass of all the compounds you need. This method prevents any of the error that would result from the reaction since no copper is lost during this reaction and this also prevents the error from copper oxidizing or copper being dropped since the copper is never given the chance to react. In addition this process involves very little error since percentage composition is a known, definite, empirical amount with a negligible uncertainty and only the copper(ii) oxide actually has significant uncertainty. If one wants to resolve the issue of the vigorous reaction of copper(ii) chloride, one could simply turn down the heat so that the reaction is not as vigorous. In this case, heating a substance during a reaction will just lead to an increased rate of reaction. However, if the temperature is reduced, then the reaction will occur more slowly but the risk of losing the copper is reduced. If one wants to resolve the issue of the oxidization of the copper then one could simply watch over the copper or come at an earlier time(i.e: the morning) so that the amount of copper that has oxidized is minimized. The evaporation of the water on the copper would not take 24 hours, realistically it would probably only need 1 or 2 hours to occur. After these one or two hours one could come in to the lab and mass the copper. This ultimately minimizes the amount of oxidized copper. ?? ?? ?? ?? ...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. Investigate the rate of reaction of luminol in various factors. The objective was to ...

    large, but I just use the axis, which is easier and also gives a more accurate value. The graph of the data would be: There is a part missing in 0.18M to 0.24M, as I mentioned before, that the 3 points are not on the curve, the tangents cannot be drawn.

  2. The purpose of this lab was to observe chemical changes, to write balanced equations, ...

    Chloride solution and Sodium Hydroxide solution Cobalt (II) Chloride: -liquid (solution) -no odour -transparent -reddish in colour Sodium Hydroxide: -transparent -colourless -odourless -liquid (solution) -dark blue in colour -starts fogging becomes translucent, almost opaque at one point -solid precipitate formed which settled at the bottom of the test tube which starts off being blue then changes to a

  1. Lab Experiment : The change in mass when magnesium burns. (Finding the empirical formula ...

    However, I know from the literature value of Mg/O = 1.00,because the reaction between magnesium and oxygen creates magnesium oxide, an ionic compound. Since the magnesium cation has a +2 charge and oxygen anion has a -2 charge, the real formula would have to be MgO, resulting in an Mg/O ratio of 1.

  2. The purpose of this experiment was to determine the molar mass of carbon dioxide ...

    = 41.9 g mol-1 Extra questions: 1) What value does the experiment give for the relative molecular mass of CO2? The relative molecular mass of CO2 was 41.9. 2) Calculate the density of CO2 at s.t.p from your results.

  1. Determining the activation energy of a reaction, By using the experimental data and the ...

    The data also corresponds well to general literature values. Although literature data on this type of experiment could not be found, results from the following reaction: 2HI(g) H2(g) + I2(g) can be used too1. The data is shown below: Table 3: Determining the rate constant (k) and ln k in the decomposition of hydrogen iodide Temperature (T)/ K 1/T K-1 Rate constant (k)

  2. To determine the molecular mass of an unknown alkali metal carbonate, X2CO3.

    Mass of substance Z used = 1.5g Trial 1 Trial 2 Trial 3 Volume of substance Z solution (±0.03cm3) 25.0 25.0 25.0 Volume of HCl required for neutralization (±0.10cm3) 27.6 28.1 27.9 Mass of substance Z used = 2.0g Trial 1 Trial 2 Trial 3 Volume of substance Z solution (±0.03cm3)

  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. Electrolysis of copper sulphate

    = final mass - Initial mass The results are shown in the table. Average mass gained for each of the trials was calculated by the following equation: C1+C2+C3+C4+C55= Average â mass (mass deposited) The results are shown in the table.

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