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

The purpose of this lab was to calculate the heat of formation for magnesium oxide (MgO).

Extracts from this document...

Introduction

The Heat of Formation of MgO Iqra Abbasi 11/19/2012 ________________ Heat of Formation of MgO (DCP and CE Lab) 9/28/2012 Data and Observations Table 1: Raw Data Collection: Mg(S) +2HCl (aq) →MgCl2 (aq) +H2 (g) Trial 1 Initial mass of Magnesium (Mg) g/±0.0001 0.1253 Initial temperature of HCl/°C/±0.2 22.1 Final temperature of HCl/°C/±0.2 27.4 Volume of HCl/mL/±1 100 Table 1: represents the raw data for the above equation Qualitative Observations: 1. When the magnesium strip was added in the hydrochloric acid, the resulting reaction was bubbling and a release of gases 2. Saw the release of gases as vapor, a distinct smell like rubber 3. After a minute or so, the reaction ceased as the magnesium strip dissolved and the hydrochloric acid returned to the same consistency as water but remained bubbly Table 2: Raw Data Collection: MgO(S) +2HCl (aq) →MgCl2 (aq) +H2O (g) Trial 2 Initial mass of Magnesium Oxide (MgO) g/±0.0001 1.5064 Initial temperature of HCl/°C/±0.2 21.9 Final temperature of HCl/°C/±0.2 33.5 Volume of HCl/mL/±1 100 Table 2: represents the raw data for the Magnesium oxide Qualitative Observations: 1. When the magnesium oxide powder was added to the hydrochloric acid, there was no immediate reaction 2. ...read more.

Middle

Solution: QHCl = mHCl. cHCl. âTHCl QHCl = 100g×4.18J/g°C×11.6°C QHCl= 418J/°C × 11.6°C QHCl= 4848.8 J QHCl= 4.8488 kJ 1. Calculate the moles of the MgO burned. 2. Solution: nMgO = nMgO = nMgO = 0.03737mol ± 0.0066% nMgO = 3.73x10-2 mol±0.0066% 1. Calculate the molar heat of formation of MgO in kJ/mol. Use Molar heat = Q (in kJ) / mol of wax. Remember to convert to kJ 2. Solution: âHMgO = âHMgO= âHMgO = -129.75kJ/mol±4.446% Table 6: Final Uncertainty Calculations for Trial 1 Uncertainty Calculations Percent Uncertainty Absolute Uncertainty Total uncertainty of Q 4.44% Moles of magnesium oxide (MgO) 0.0066% Uncertainty of âHMgO 4.44% +0.066% = 4.446% 129.75kJ/mol x 0.044446 = ± 5.7686 Therefore the âHMgO is -1.3 x 102 ± 6.0 kJ/mol Calculate the âH of the equation H2 (g) + ½ O2 (g) → H2O (l) Using Hess’s Law: âHf (reactants) - âHf (products) âHf (reactants) - âHf (products) = -286 kJ/mol Table 7: results of âHf for all equations âHf/ Reaction magnesium -429.841 ± 37.0515 kJ/mol Mg(S) +2HCl (aq) →MgCl2 (aq) +H2 (g) magnesium oxide -129 ±5.7686 kJ/mol MgO(S) +2HCl (aq) →MgCl2 (aq) ...read more.

Conclusion

Another reason to conduct this experiment in a closed system would be because the temperature in the room where the experiment was conducted may have fluctuated creating inconsistency within our calculations. There was also the assumption that the density of the hydrochloric acid was the same as water. If the proper or accurate density was used, there could have been more accurate results. These minimal errors can be evaded in further investigations by changing some of the equipment used to gather data. To ensure that a proper temperature is recorded, a temperature probe with uncertainty in the hundredth decimal place would give accurate results. Another way to minimize error would be do a different set-up to make certain that heat loss is prevented. To do that, instead of using a Styrofoam cup, a calorimeter can be used. If a calorimeter is unavailable, than adding a lid to the cup would diminish the error significantly. Another way to further improve the experiment would be to determine the actual density and specific heat of HCl, by doing this our results would be more accurate in terms of the solution used. ...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. Experiment - The Empirical Formula of Magnesium Oxide

    It can be seen that the amount of magnesium is proportional to the amount of oxygen. The gradient of the line of best fit is 0.6005. The positive gradient indicates that an increase in the amount of magnesium will result in a proportional increase in the amount of oxygen.

  2. Acids/Bases Design Lab. How does a change in the pH value of a solution ...

    Steps 1-13 were done for two more trials to ensure precision in the data collected. However, the beaker labels for trial two were: CT2/CRT2 and trial three: CT3/CRT3 16. The lab area was cleaned, and hands were washed. Any solid waste remaining was placed in a designated waste container, and any liquid waste was disposed of accordingly.

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

    �specific heat capacity of water= 4200 J/kg �C �change in temperature= 7 �C Q (energy)= m(mass of HCl solution)* c(specific heat capacity of water) *?T (temperature change) Q = 0.05kg x 4200 J/kg�C x 7 �C = 1680 J = 1.68 kJ it is necessary to show by calculation, that

  2. Molar Heat combustion chemistry - investigate the effect of molar mass on the molar ...

    Accepted Values of Molar Heat of Combustion Percentage Difference (%) Methanol 312.92 726 132.01 Ethanol 466.46 1367 193.06 1-Propanol 1037.45 2021 94.80 1-Butanol 1194.44 2676 124.04 1-Pentanol 1127.08 3329 195.37 Conclusion and Evaluation: The aim of this experiment is to investigate the effect of molar mass on the molar heat

  1. Titration of Na2CO3.xH2O with HCl

    By using the mean volume of HCl, I calculated the concentration of Na2CO3. Then I used this to calculate the number of moles of Na2CO3, and with a few more calculations I used this value to find 'x' (the number of moles of water of crystallization of Na2CO3).

  2. Finding thr Percentage Composition of Magnesium Oxide

    Calculate the percentage composition of magnesium oxide using your experimental data from Part A. The percentage composition of magnesium is 61.76% and the percentage composition of oxygen is 38.24%. 1. Calculate the percentage composition of magnesium oxide using your experimental data from Part B.

  1. Bomb calorimetry. The goal of this experiment was to use temperature data over ...

    + 3 H2O (l) + 26.434 kJ/g (1) Cotton + O2 ï® Products + 0.059 kJ (2) C10H8 (s) + 12 O2 (g) ï® 10 CO2 (g) + 4 H2O (l) + âcUo (3) The first law of thermodynamics states that “energy can neither be created nor destroyed, but can be transformed from one state to another.” âcU = q + w (4)

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

    + 2HCl (aq.) + MgCl2 (aq.) + H2O (g) + H2 (g) + O2 (g) MgCl2 (aq.) + H2 (g) + MgO (s) + 2HCl (aq.) + H2O (g) * Mg (s) + O2 (g) MgO (s) Since reaction 2 was reversed, the sign on the value of ?HY was

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