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

Determining an enthalpy change of reaction

Extracts from this document...

Introduction

Determining an enthalpy change of reaction Design Aim The purpose of this experiment is to determine the enthalpy change for the displacement reaction: Zn(s) + Cu2+(aq) � Cu(s) + Zn2+(aq) Introduction By adding an excess of zinc powder to a measured amount of aqueous copper (II) sulphate, and measuring the temperature change over a period of time, you can than calculate the enthalpy change for the reaction. Requirements ? safety spectacles ? pipette, 25 cm3 ? pipette filler ? polystyrene cup with lid ? copper (II) sulphate solution, 0.5 M CuSO4 (harmful if swallowed) ? weighing bottle ? spatula ? zinc powder ? balance ? thermometer, 0-100?C (0.1? graduations) ? watch or clock with second hand Procedure 1. Pipette 25.0 cm3 of the copper (II) sulphate solution into a polystyrene cup. 2. Weigh about 1 g of zinc powder in the weighing bottle. Since this is an excess, there is no need to be accurate. ...read more.

Middle

At the 180-second interval, we added the zinc. It first floated on the surface of the solution but as we continued to stir, it mixed with the solution, taking on a shade closer to brown. The solution reflected that same brown color as we started but then changed color too, taking on a darker tinge of blue. By the end of the experiment, we could observe excess zinc resting on the bottom of the cup. The solution had actually turned shades lighter. Data Processing: I will first calculate the averages of all three sets of trials to represent the temperature change of the solution. I will then plot the temperature (y-axis) against time (x-axis), as well as extrapolate the curve to 3.0 minutes to establish the maximum temperature rise. Next, I will calculate the enthalpy change for the quantities used, making appropriate assumptions. Finally, I will calculate the enthalpy change for one mole of Zn and CuSO4(aq), and write the thermochemical equation for the reaction. ...read more.

Conclusion

Sample calculations: error = [(-99.87 - (-217)) / (-217)] x 100% = 53.98 My calculations revealed that there was a percentage error of over 53%. Limitations Suggestions for Improvement Heat continued to escape from top of the cup Maybe place a lid on the cup to contain the heat within the cup and that way not much heat is being lost or use a calorimeter if it were possible to obtain one When calculating the enthalpy energy of the reaction, we substituted C with the specific heat capacity of water. By using the actual specific heat capacity of the CuSO4 solution We substituted the amount of zinc powder as dictated by the experiment sheet (6g) with only 1g. Perhaps, this significantly lower concentration of zinc can be held accountable for the significantly low deviation in degrees after the zinc was added. Actually add 6 grams of zinc which is the approximate equivalent of 1 mol of zinc and what was asked for by the experiment sheet. The change in temperature might result in the expected maximum temperature and greater degrees between each time interval. ?? ?? ?? ?? ...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. Electrochemical cells - investigate the effect of the temperature change of the anode electrolyte ...

    - The distance of salt bridge: the salt bridge should be the same, however in the experiment, the distance of salt bridge always vary , and the immersion of salt bridge in each solution is changing during the experiment, especially for the repeated experiments, the distance of salt bridge hard

  2. Thermodynamics: Enthalpy of Neutralization and Calorimetry

    Using the new solution made by mixing the NaOH and HCl, NaCl the specific heat of NaCl can be found. The calorimeter is emptied rinsed and dried and the NaCl put in a separate beaker. 50.0 mL of the NaCl solution are weighed and placed in the calorimeter and temperature is taken.

  1. IA-Enthalpy Change of Reaction - Zinc and Copper Sulphate.

    The lid was made of thin plastic and was not airtight, so an easy pathway for heat loss was created. * A metallic stirring chip was used in this experiment and the temperature probe was submerged into the solution. Since only a small amount of chemicals was used, the chip

  2. Electrolysis of copper sulphate

    1. Fourth current reading is 0.8 amps. Total Quantity of charge = Current Ax TimeS â 0.8 x 120 = 96 Coulombs 1. To find number of electrons transferred. Number of e- =Total Quantity of ChargeCharge of 1e- â961.60217733x10-19= 6 x1020electrons 1.

  1. Measuring the fatty acid percentage of the reused sunflower oil after numerous times of ...

    as it is going to be Molarity number of moles volume M n V alcoholic. For 0.01M: 10 0.01 number of moles 1L n 0 .01 0 .01 moles ASLAN Özge Cemre D129077 0.01 moles of KOH x 56 .109 g KOH 0.561 0.001 grams of KOH 1 1 mole of KOH must be used for 0.01M solution.

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

    is still 16.1% off. The experiment was carried out with the maximum possible care to avoid any errors however, there still were several limitations in the apparatus and several assumptions made that have led to the this high degree of inaccuracy.

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

    24.0 24.0 24.0 0 24.0 24.0 24.0 24.0 15 28.5 29.0 30.5 29.0 30 31.0 33.0 34.0 33.0 45 39.0 36.0 37.0 37.0 60 43.0 45.0 46.5 45.0 75 46.5 47.5 48.0 47.5 90 50.0 52.0 53.0 52.0 105 60.0 61.5 62.0 61.0 120 67.5 66.0 67.5 67.5 135 77.5

  2. Analysis of the Standard Enthalpy of Combustion for Alcohols

    The uncertainty is found using the half range rule – 1.09 g -0.94 g2=0.075 g =1.02 g 0.075 g =1.02 g ± 0.074% The absolute uncertainty is usually converted to the percentage uncertainty which is rounded to 1 significant figure, however to prevent premature rounding I’ve given the percentage uncertainty to 3 decimal places.

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