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

Using Calorimeter Techniques to Indirectly Determine An Enthalpy Change Using Hess Law

Extracts from this document...


Name: Vo Ngoc Kieu Duyen - Cher Date : April 5th 2011 IB Chemistry HL Mr. Brendt Bly Internal Assessment: Title: Using Calorimeter Techniques to Indirectly Determine An Enthalpy Change Using Hess' Law Aim: Determine an enthalpy change using Hess' Law and calorimeter techniques. Procedure: IB Chemistry Investigations - Volume 1 - Core. Data Collection and Processing: Table 1: The volume of 2 mol dm-3 hydrochloric acid and mass of sodium hydrogen carbonate and mass of weighing bottle & sodium hydrogen carbonate when measuring. Volume of Hydrochloric acid (HCL) 100.5 � 0.01 grams Mass of Sodium hydrogen carbonate 14.08 � 0.01 grams Mass of weighing bottle and NaHCO3 41.73 � 0.01 grams Mass of weighing bottle before adding NaHCO3 27.62 � 0.01 grams Mass of weighing bottle after putting NaHCO3 into Hydrochloric acid (HCL) 27.62 � 0.01 grams Table 2: The temperature change during the reaction of Hydrochloric acid and Sodium hydrogen Carbonate Time (s) ...read more.


and Sodium Carbonate (Na2CO3) Calculations: Part 1: HCl + NaHCO3 reaction Change in temperature (?T): ?T = 18.2 �C - 28.0 �C ?T = -9.85 � 1 �C Q = mc(?T) Q = (-9.8 �C)(4.18 J/g�C)(100.5 g) Q = 4116.8 J Q � - 4.12 kJ Sign of Q must be opposite with the sign of delta H. Therefore, Q = 4.12 kJ. Mol NaHCO3 = 14.08 g NaHCO3 ( = 0.167 mol � 0.17 mol NaHCO3 ?H = = 24.23 kJ mol-1 Part 2: HCl + Na2SO3 reaction Change in temperature (?T): ?T = 34.1 �C - 24.2 �C ?T = 9.9 � 1 �C Q = mc(?T) Q = (9.9 �C)(4.18 J/g�C)(100.5 g) Q = 4158.891 J Q � 4.16 kJ Sign (charge) of Q must be opposite with the sign (charge) of delta H. Therefore, Q = -4.16 kJ. Mol Na2SO3 = 8.08 g Na2SO3 ( = 0.076 mol � 0.08 mol Na2SO3 ?H = = - 5.2 kJ mol-1 Enthalpy change calculation: 2NaHCO3 (s) ...read more.


Since I have a high percentage error of 87%, I came up with some random errors that could have occurred throughout our experiment: I have to use an analogue thermometer and I have to open the cup to check the temperature so the reaction might not have the accurate result it is affected by the surroundings. The heat might have spread out to the atmosphere around it when I opened the cup to check the temperature in the second experiment. In the first one, the temperature might be affected by the heat from the surroundings and it couldn't reach the coolest point. Next time, I should use an electric probe (digital thermometer) to minimize the heat loss or heat gain to/from the surroundings. Another thing that has could gone wrong is that throughout the experiment, I put the substance in the acid bit by bit and I moved the cup in circular motions a lot; that could be an error. Because the acid didn't have the enough amount of sodium to react so the results were not very accurate. ...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. Hess's Law. The experiment conducted was meant to determine the enthalpy of formation of ...

    and CaO(s). Through experimentation, it was determined that the enthalpy of formation of MgO(s) is - 540 kJ/mol � 1.8 kJ/mol, with 10.5% percent error when compared to the accepted value, and for CaO(s) it was -330 kJ/mol � 2.9 kJ/mol, with 48.5% percent error.

  2. Calcium Carbonate and Hydrochloric Acid

    The reason data recording stopped was that 3 recording in a row showed the same data. The possible reason for the 3 recording to show the same data could be that the gas that was trying to escape fell down again and the gas that escaped in that time period could not be detected by the scale.

  1. Can one determine the coefficients of a balanced chemical equation by having the mass ...

    Hence the conclusion is judged to be inconclusive because there were so many errors that came into effect that altered the value of the mass of the copper and aluminum. Evaluating Procedures The procedure in determining the balanced chemical equation of the reaction between copper(ii)

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

    Mg MgO Errors Mass 0.25 g 0.40 g +0.01g Volume acid used 50 cm3 50 cm3 + 1 cm3 Temperature (�C) Trial 1 Initial temperature 21 21 + 0.5�C Final temperature 38 28 + 0.5�C Change in temperature 17 7 + 0.5�C Trial 2 Initial temperature 20 22 + 0.5�C

  1. Enthalpy Change of a Displacement Reaction

    Systematic errors must have contributed to this difference. 1) Systematic errors a) To compensate for the heat lost by the water in this reaction to the surroundings as the reaction proceeds a plot of temperature against time can be drawn.

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

    In this case, the percentage uncertainty for the readings of the digital balance was 0.67% which is the largest percentage uncertainty in comparison to the other instruments such as the burette or the pipette. If these uncertainties could be avoided a result much closer to the literature would be possible to obtain.

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

    As the equation fro the reaction states that for every mole of reacted 2 moles of HCl are reacted it means that a total of .038 of HCl so we can establish that is the limiting reactant as .03 moles of would be needed to react the .06 moles of HCl but we only have 0.019 and 0.28.

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

    28.0 60 35.0 34.0 34.5 34.5 75 43.0 42.0 41.0 42.0 90 48.0 47.5 46.0 47.5 105 50.0 49.0 49.0 49.0 120 53.0 52.5 51.0 52.5 135 59.5 59.0 56.5 58.0 150 58.0 58.5 56.0 57.5 165 57.5 58.0 55.5 57.0 180 57.0 57.5 55.0 56.5 210 56.5 57.0 55.0

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