• 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. A comparison of various proprieary antacids

    was more effective than the other by seeing the number of moles of hydrochloric acid neutralised, this may not give a proper justification as to the performance of each antacid. The stomach is a much more complex organ whereby there are lots of specialised cells performing specific functions.

  2. Enthalpy Change Design Lab (6/6)How does changing the initial temperature (19C, 25C, 35C, and ...

    or 1.00 mol dm-3 KOH(aq) so that the base of the temperature probe is touching the base of the 150 cm3 beaker. 9. The temperature readings of both Vernier LabQuest LoggerPro data collection units were monitored, and once one of the solutions of either 40.0 cm3 of 1.00 mol dm-3 KOH(aq)

  1. Electrochemical cells - investigate the effect of the temperature change of the anode electrolyte ...

    In this experiment, some variables were not very well controlled, it will invlove some random errors, the error has an equal chance of being postive or negative; where as the systematic error are inherent in a particular apparatus such as hot plate, the error is generally reproducible and it affects the results in the same way each time.

  2. Chemistry Lab- Determining enthalpy change of a reaction. Adding zinc to copper ...

    can be obtained from the graph, as shown below: Note: The horizontal error bars for time, were too small to be visible on the graph. 3. Substituting these values into the equation we obtain the Enthalpy Change of the reaction: Q = mc ?T = (31.02 � 0.02g)

  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

    Fifth current reading is 1 amp. Total Quantity of charge = Current Ax TimeS â 1x 120 = 120 Coulombs 1. To find number of electrons transferred. Number of e- =Total Quantity of ChargeCharge of 1e- â481.60217733x10-19= 7.5 x1020electrons 1.

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

    = m (CH3OH)M (CH3OH) = 1.59 g32.05 g mol-1 = 0.0496 mol The enthalpy of combustion of methanol from here is : ?Hc (CH3OH) = Heat energy transformed to the waterAmount of methanol burnt = 4.36 kJ0.0496mol ?Hc (CH3OH)

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

    ±0.10 15.0cm3 = 0.36% Digital Balance (g) ±0.01 0.05g = 20% Total Random Error 0.78 + 0.36 + 20 = 21.14% Table 8: Total Random Error Calculation for Part Y Total random error = 21.14% Therefore, absolute error = = 22.5 Therefore, ΔHY = -106.3±22.5kJ.mol-1 Step 3: Calculating total absolute

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