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

Chemistry Enthalpy Change

Extracts from this document...


Investigation of Enthalpy Change Data Processing Since the mole ratios of zinc and copper are the same in the reaction that took place: Zn(s) + Cu2+(aq) --> Cu(s) + Zn2+(aq) Molar EnthalpyZn = Molar EnthalpyCu2+ Conclusion: In conclusion, the redox reaction involving zinc and copper (II) is an exothermic reaction which occurred in a closed system. This is due to the increase in temperature of the surroundings, copper (II) sulfate, from an initial temperature of 20.0 � 0.5 ? C to a final temperature of 45.0 � 0.5 ? C which can be observed in the table. In addition, the graph above shows the temperature of the surroundings in relation to time, which further proves these results. Because the temperature of the surroundings increased, this meant that the system (reaction between zinc and copper (II) ) lost energy resulting in a decrease in enthalpy. Once the temperature stabilized at 45.0 � 0.5 ? C, it was observed that excess zinc remained in the Styrofoam cup. Furthermore, the theory is further proven in the calculations conducted regarding enthalpy change. Since ?H was calculated to be -2100�100J, which is a negative number, it is, thus, an exothermic reaction. ...read more.


Thus, the cups were cut smaller in order for accurate readings to be read from the thermometer. Nevertheless, the cups no longer fit perfectly together and there were gaps left between the cups leaving room for energy to be transferred between the calorimeter and the air in the room, despite taping the cups together. Next, the precision of the measuring devices inhibits the results of the experiment to match the accepted value of enthalpy change. Because there are uncertainties in all the equipment used, there is a margin of error associated with each apparatus. Nevertheless, the margin of error increases with consecutive calculations regarding enthalpy change. Thus, all calculations will not be completely accurate leading to discrepancies between experimental and accepted values. Also, this weakness is insignificant in comparison to the inefficiency of the calorimeter used and is difficult to circumvent. Moreover, a less significant weakness is involved with the transferring of solutions. When transporting the copper (II) sulfate solution from the pipette to the Styrofoam cup, some droplets of the solution were left behind in the pipette. Nevertheless, this does not make a large difference in the overall experiment, therefore making it a less significant weakness. ...read more.


Nevertheless, if this is not available, smaller Styrofoam cups could be used in the polystyrene calorimeter therefore preventing one's self from cutting large cups that do not fit together. Next, even though uncertainties were associated with all measuring devices, the most precise equipment available was used to prevent large uncertainties. For example, a pipette was used to measure the copper (II) sulfate solution instead of a beaker, which has a larger uncertainty associated with it. Furthermore, a scale with a very small uncertainty was used rather than a scale with a larger uncertainty. In the future, the usage of the most precise equipment should be used, such as a more precise weighing scale and pipette. In addition, in order to prevent some of the zinc powder from being left behind, a more solidified sample of zinc should be used. Therefore, the measured quantity of zinc would be the same as the amount of zinc actually transported to the calorimeter, even though zinc was added in excess to this experiment. Also, a stirring rod could be used in order to ensure that both reactants mix thoroughly. Lastly, human error is unavoidable. Nevertheless, In order to minimize this, one should be more careful when handling equipment and measuring devices. ...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. A comparison of various proprieary antacids

    The volume of Hydrochloric acid (HCl) added to each antacid- 25 cm3 of HCl will be used for all trials, for all antacids. Amount/ dosage of each antacid-the maximum dosage of each antacid will be used as per the intrustion guide on the antacid packages. Therefore 2 tablets of Actal Tums per Trial, 1 sachet of

  2. IB chemistry revision notes

    The silver chloride p.p.t. dissolves easily in ammonium hydroxide (ammonia). 3. In the case of Bromide Ions, a cream p.p.t. is produced which also decomposes with light and turns grey. However, it doesn't dissolve in ammonia. 4. In the case of Iodide ions, a yellow p.p.t is produced which does NOT decompose with light.

  1. Hesss Law Lab, use Hesss law to find the enthalpy change of combustion of ...

    There is a lot of room for improvement and all those errors can be prevented to obtain better results which will be much closer to the Table values. The following changes can be made in order to improve the experiment by a great deal.

  2. Thermodynamics: Enthalpy of Neutralization and Calorimetry

    -2141.598 cal -2099.297 cal -2435.453 cal Moles of NaOH neutralized .1 mol .1 mol .1 mol Enthalpy of neutralization of NaOH kcal/mol -30.65 �.072 kcal -21.42 kcal/mol -20.99 kcal/mol -24.36 kcal/mol Enthalpy of neutralization of NaOH kJ/mol -128.24 �. 072 kJ/mol -89.604 kJ/mol -87.835 kJ/mol -101.90 kJ/mol Heat Capacity of

  1. Effect of Current on The Quantity of Products in Copper Purification Through Electrolysis

    � une concentration de 0,1 mol/L pr�par� aux �tapes 3-5 dans le contenant en verre de la pile. Ceci garde constant les variables de volume d'�lectrolyte ainsi que sa manipulation. 14. Placer les �lectrodes de cuivre afin que leurs extr�mit�s touchent au fond du contenant et serrer avec le support � �lectrodes pour garder le montage constant.

  2. Measuring the Enthalpy Change for the reaction

    sulphate used in the experiment: Volume x concentration = 50.0 x 0.500 = 0.0250 moles 1000 1000 Moles of Zinc power used in the experiment: Mass = 4.761 = 0.07283 mr 65.37 =0.0728(3s.f) In the method given, I was asked to weigh out the mass of the Zinc powder between 4.5g and 5g.

  1. The aim of this experiment is to examine the enthalpy of combustion of the ...

    = 52K Knowing this , we can calculate the total amount of energy that has been transformed to water : Q = 40.0 g * 4.20 J g-1 K-1 * 52 K Q = 8736J = 8.73 kJ Mass of Methanol used in experiment : m (CH3OH)

  2. To determine the standard enthalpy of formation of Magnesium Oxide using Hess Law.

    However, under the material and time limitations, this was the best type of calorimeter that could be devised. An example of a more sophisticated calorimeter that could be used is a simple thermos flask which to a large extent minimizes heat loss due to conduction, convection and radiation.

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