• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month
Page
  1. 1
    1
  2. 2
    2
  3. 3
    3
  4. 4
    4
  5. 5
    5
  6. 6
    6
  7. 7
    7
  8. 8
    8
  9. 9
    9
  10. 10
    10
  11. 11
    11
  12. 12
    12
  13. 13
    13
  14. 14
    14
  15. 15
    15
  16. 16
    16

The Enthalpy of Neutralization

Extracts from this document...

Introduction

Enthalpy of Neutralization Data Collection Experiment 1 - The reaction between hydrochloric acid and sodium hydroxide. Table 1.1: Temperature of HCl and NaOH, separately and after mixing Reagent Temperature (�C) for Trial 1 Temperature (�C) for Trial 2 25cm3 of 2.00mol�dm-3HCl 21 � 0.5 21 � 0.5 25cm3 of 2.00mol�dm-3NaOH 21 � 0.5 21 � 0.5 Mixture of HCl and NaOH 34 � 0.5 34 � 0.5 Change in temperature (?T) -13 � 1.0 -13 � 1.0 Experiment 2 - The reaction between hydrochloric acid and potassium hydroxide. Table 2.1: Temperature of HCl and KOH, separately and after mixing Reagent Temperature (�C) for Trial 1 Temperature (�C) for Trial 2 25cm3 of 2.00mol�dm-3HCl 20 � 0.5 21 � 0.5 25cm3 of 2.00mol�dm-3 KOH 20 � 0.5 21 � 0.5 Mixture of HCl and KOH 32 � 0.5 33 � 0.5 Change in temperature (?T) -12 � 1.0 -12 � 1.0 Experiment 3 - The reaction between nitric acid and sodium hydroxide. Table 3.1: Temperature of HNO3 and NaOH, separately and after mixing Reagent Temperature (�C) for Trial 1 Temperature (�C) for Trial 2 25cm3 of 2.00mol�dm-3 HNO3 20.5 � 0.5 21 � 0.5 25cm3 of 2.00mol�dm-3NaOH 20.5 � 0.5 21 � 0.5 Mixture of HNO3 and NaOH 33 � 0.5 34 � 0.5 Change in temperature (?T) -12.5 � 1.0 -13 � 1.0 Experiment 4.1 - The reaction between sulfuric acid and 2.00mol�dm-3 sodium hydroxide. ...read more.

Middle

x (4.18J�g-1�k-1) x (-12.75) = -2665J (-12.5 + -13) � 2 Conversion of Uncertainty to Relative Error [(Nearest unit of volume measurement observed � desired volume) x 100 = Percentage error of volume] (1�50) x 100= 2% [(Nearest unit of temperature measurement observed � recorded temperature) x 100 = Percentage error of recorded temperature] (1�12.75)x100= 7.8% [Percentage value of volume error + percentage value of temperature error = relative error] 2%+7.8% = 9.8% relative error Enthalpy change in joules with relative error percentage Q= -2665J � 9.8% Conversion of Relative Error to Absolute Error (2665�100) x 9.8= 261 Absolute Uncertainty = �261J --> Q= -2665J � 261J (�1000) [To change to kilojoules] Q= -2.67 kJ � 0.261kJ (�0.050mol H2O) [To find kilojoules per mole of water] Q = -53.4 kJ�mol-1 H2O (� 5.22 kJ�mol-1 H2O) Calculating Percentage Error of Observed Enthalpy Value [(Observed Value - Expected Value) � Expected Value] x 100 = Percentage error [(-53.4 kJ�mol-1 H2O (� 5.22 kJ�mol-1 H2O) - -57.6 kJ�mol-1) � -57.6 kJ�mol-1] x 100 = 7.47% Experiment 4.1 - Enthalpy of neutralization for sulfuric acid and 2.00mol�dm-3 sodium hydroxide 2NaOH(aq) + H2SO4(aq)--> Na2SO4(aq) + 2H2O(l) Finding the Moles of Water Moles of sulfuric acid: [Volume x Concentration] 0.025dm3 x 2.00mol�dm-3 = 0.050mol H2SO4 Moles of sodium hydroxide: [Volume x Concentration] 0.025dm3 x 2.00mol�dm-3 (x 2) = 0.100mol NaOH Moles of water: [Equal to moles of limiting reagent] 0.050 H2SO4 --> 0.050mol H2O (x2) ...read more.

Conclusion

volume, while our thermometer had an uncertainty of plus/minus 0.5�C, giving us a varying absolute error value depending on our recorded result. Evaluation As stated in our conclusion, there were many possible sources our errors throughout the experiment could have come from. Systematic errors include the degree of precision for our instruments and materials, and we could improve the experiment's accuracy by having simply more precise equipment such as measuring beakers with a 0.05ml uncertainty rather than 0.5ml, or a data logger to measure temperature rises rather than having students observe and measure, making the reading susceptible to random errors such as parallax and simply human error. Another factor not taken into account was the room temperature, though kept more or less even, it was not constant, and therefore could have affected the experiment's results if it had changed the temperature of the reagents or final solution by even one degree. To improve on this possible error, we could attempt the experiment in a space where the temperature is constant. Seeing as temperature would be a prime affected factor in the experiment we also have to take into account the fact that by simply touching the materials (measuring beakers, thermometers etc.) that we may also be passing heat on through means of conduction by our own bodies/hands. So to improve upon this, we could have attempted the experiment wearing insulating gloves to reduce heat given off by ourselves to the materials. ?? ?? ?? ?? IB Chemistry 2 1 ...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. IB IA: Determination of Heat of Neutralization

    when 1 mole of hydrogen ions, H+ reacts with 1 mole of hydroxide ions, OH- under standard conditions, which are 298K and 1 atm. 2. The table below shows examples of some neutralization reactions and the theoretical value of each reaction's standard enthalpy change of neutralization.

  2. Thermodynamics: Enthalpy of Neutralization and Calorimetry

    In this experiment the base was NaOH and the acid HCl. The experiment goes on to test the specific heat of NaCl in a similar manner as that of the metal cylinder. Methods To make the calorimeter, two Styrofoam cups are placed together.

  1. Airbag design lab. Is it possible to use baking soda, NaHCO3(s), and 2.00 ...

    The following was done in the experiment. The amount of reactants needed was determined by finding the volume of the ziploc bag where the reaction took place. The ziploc bag was filled with water then dumped into a graduated cylinder to determine the volume of the bag.

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

    Hence, with the molar enthalpies of the three intermediate chemical reactions, the heat of combustion for magnesium was calculated algebraically. The values obtained experimentally are slightly different and inconsistent to those of table values. If these results are compared to the accepted value of - 602 kJ/mol it can be

  1. Measuring the Enthalpy Change for the reaction

    I will then use the values that I have worked out from the previous calculation to work out that molar enthalpy change for the reaction: ?H = -q = -5872.9 = -234.9 Moles x 1000 0.0250 x 1000 = -235(3s.f)

  2. Experimental Molar Enthalpy of Neutralization for Sodium Hydroxide Solution

    value (the reason for this will be discussed later in the conclusion); however, this was not the case in this lab. There are a variety of reasons why the experimental enthalpy change for this lab was greater than the theoretical (actual)

  1. Lab report. Finding the molar enthalpy change of the reaction between Hydrochloric acid and ...

    For we know the mass so in order to fin the number of moles we divide the mass by its molar mass so getting .019 moles when we used 2 grams while when we used 3 grams we got 0.28.

  2. Analysis of the Standard Enthalpy of Combustion for Alcohols

    Material glassware Use the same brand and materials of a conical flask for all trials. Different materials have different conductivity and may absorb more heat from the alcohol lamp, affecting the overall heat absorbed by the distilled water. Using the same material and brand of conical flask ensures that this is the same for each experiment.

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