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

Energetics Design Lab

Extracts from this document...

Introduction

Rammy Abssi Chemistry - 11 May 04, 2009 Energetics Planning Lab Research Question: How does the strength of the acid, affect the change in temperature of a reaction with sodium carbonate (acid-base reaction)? Hypothesis: I believe that if acid is stronger, than the change in temperature of the acid-base reaction will be greater. Variables: Type of Variable Variable Range of Values/Method of Control Independent Variable Strength of Acid (Type of Acid) From 0.30g to 1.80g in increments of 0.30g Dependent Variable Change in Temperature Read from thermometer at the peak of reaction Controlled Volume of Acid Used 50cm3 in all trials Initial Temperature All reactions start off at room temperature (21�C - 22�C) The Base Which the Acid is Reacted With Sodium Carbonate Na2CO3 Materials: * Copper cup * Styrofoam cup * Lid for copper cup * Total of 31.80 grams of sodium carbonate (� 0.005g) * 150ml hydrochloric acid (� 0.5ml) [50ml each trial] * 150ml sulfuric acid (� 0.5ml) [50ml each trial] * 150ml ethanoic acid (� 0.5ml) [50ml each trial] * Balance (� 0.005g) * Thermometer (� 0.5�C) * Stirrer Diagram: Method: There will be three trials for each of the three different types of acids. Using 9 weighing boats split the sodium carbonate into 6 sets of 2.65 grams and 3 sets of 5.30 grams. ...read more.

Middle

Hydrochloric Acid: 1 = (x * 50) / 1000 x = 50 / 1000 x = 0.05 There are 2 moles of Hydrochloric Acid 0.05 / 2 = 0.025 0.025 x 106 = 2.65g Ethanoic Acid: There are also two moles, therefore its also 2.65g Sulfuric Acid: There was only one mole of sulfuric acid, therefore the amount of sodium carbonate is 5.30g Hydrochloric: Na2CO3 + 2HCl --> 2NaCl + H2O + CO2 How much heat was evolved? q = mC?T q = (52.65)(4.18)(3.3) q = 726.3J = 0.73kJ How many moles of H+? 1mol HCl = 1 mol H+ ? mol H+ = 1.00 x 0.0500 = 0.0500 mol H+ How much heat/mol H+? ?H (neutralization) = 0.73/0.0500 = -14.6 kJ/mol % Error ((-14.6 - -57.1)/-57.1 ) x 100% = 74.4% Sulfuric: Na2CO3 + H2SO4 --> Na2SO4 + H2O + CO2 How much heat was evolved? q = mC?T q = (55.30)(4.18)(6.5) q = 726.3J = 1.5 kJ How many moles of H+? 1mol H2SO4 = 2 mol H+ ? mol H+ = (1.00 x 0.0500)/2 = 0.025 mol H+ How much heat/mol H+? ?H (neutralization) = 1.5/0.025 = -60.0kJ/mol % Error ((-60 - -57.1)/-57.1 ) x 100% = 5.08% Ethanoic: Na2CO3 + 2CH3COOH --> 2CH3COO-Na+ + H2O + CO2 How much heat was evolved? ...read more.

Conclusion

Another limitation to this experiment is the fact that only one weak acid was used, as compared to two strong acids. Due to the fact that the school did not supply phosphoric acid, only one weak acid was available. This affects the results because the comparisons of weak acids and strong acids become limited to only two comparisons. If phosphoric acid was used than the comparisons between strong acids and weak acids would have been increased to four. All in all, this results in a more accurate conclusion. Looking at the percentage error in these experiments: Hydrochloric Acid: For hydrochloric acid, the percentage error was 77.4% however for the percentage uncertainty it is 59.7%. The percentage error was greater than the percentage uncertainty meaning this is a random error which I made in the experiment. This is most likely due to the heat loss in the experiment. Sulfuric Acid: For sulfuric acid, the percentage error 5.08%, and the percentage uncertainty was 36.8%. This means that the error was a systematic error. The value to of delta H for sulfuric acid in the experiment was very close to the theoretical value of delta H for sulfuric acid. Overall, the percentage errors for these acids were relatively very high. This could be due to the fact that calcium carbonate is a gas releasing base. Therefore, CO2 is released into the environment and a lot of heat is lost. ...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. Calcium Carbonate and Hydrochloric Acid

    As soon as all the HCl was in the flask the cotton was placed in the tube hole, on top of the flask, so that only gas (CO2) could escape, and the stop clock was started 4. The weight of the solution was recorded with 30 (� 1,0 sec)

  2. A comparison of various proprieary antacids

    Trial Number 1 2 3 Final Volume of NaOH, cm3 �0.05 cm3 26.70 23.70 23.50 Initial Volume of NaOH, cm3 �0.05 cm3 0.00 0.00 0.00 Volume of NaOH �0.1 cm3 26.70 23.70 23.50 Closest Results Colour change of mixture in conical flask Cream--> Pinkish White Volume of HCl(aq)

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

    This means they have more opportunity to collide with other substances, such as a reactant, and will therefore increase the rate at which two reactants chemically react. (Helmenstine, 2012). To ensure temperature is not a variable left unchecked in the investigation, the following steps should be taken to ensure it is controlled.

  2. IB chemistry revision notes

    * Tends to be faster in gases, slower in liquids and very slow in solids. Kinetic Theory * Pressure --> The measure of the number and speed of the molecules hitting the walls of the container per second. o If the molecules hit the container walls more often then o

  1. The Enthalpy of Neutralization

    Calculating Percentage Error of Observed Enthalpy Value [(Observed Value - Expected Value) � Expected Value] x 100 = Percentage error [(-54.3 kJ�mol-1 H2O (� 4.18 kJ�mol-1 H2O) - -57.9 kJ�mol-1) � -57.9 kJ�mol-1] x 100 = 6.21% Experiment 2 - Enthalpy of neutralization for hydrochloric acid and potassium hydroxide KOH(aq)

  2. The rate of reaction between sodium thiosulfate and hydrochloric acid

    0.0200 259.0 0.0300 140.0 0.0400 103.0 0.0500 76.70 0.0600 65.30 0.0700 56.30 0.0800 48.00 0.0900 43.00 0.1000 36.00 Table 2.2 shows the processed mean time taken for the cross to disappear of each tested concentration of sodium thiosulfate. * Calculating the rate of reaction: * Rate of reaction = 1

  1. Electrolysis of copper sulphate

    In theory, the closer the distance between the electrode pairs, the quicker the rate of electrolysis as the current would flows through the electrodes faster, therefore increasing the rate of electrolysis, consequently, increasing the mass of Cu deposited and vice versa.

  2. Determining Ka by the half-titration of a weak acid

    Finally the confidence level for my conclusion is good. I got the results expected, as method 2 will always be more accurate than method 1 as the latter depends too much on qualitative and subjective recordings. Thus my confidence level for such conclusion is good.

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