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

Energy and Rates Analysis of Chemical Reactions

Extracts from this document...


Name: Alec Cooke Partners: Erik MacPherson and Ben Murat Experiment Date: November 6th 2008. Lab 3: Energy and Rates Analysis of Chemical Reactions Due Date: November 17th 2008. Instructor: Mr. MacLean Questions (i) How does the molar enthalpy of reaction of magnesium vary with different acids, namely, hydrochloric, sulfuric, and acetic acids? (ii) How does the rate of reaction of magnesium vary with these acids? Hypothesis If magnesium is mixed into any of the aqueous acid solutions, it is predicted that there will be fizzing and bubbling. This bubbling will be due to the release of Hydrogen gas, which is produced when the hydrogen bonds are broken and replaced with the magnesium. It is hypothesized that the test tubes will be warm, because the reaction is exothermic; therefore it releases energy, or heat into its surroundings. It is also expected that the carboxylic acid (Ethanoic acid) will have a faster rate of consumption for magnesium, because its carbon base will allow it to let go of its hydrogen atoms more readily than hydrochloric and sulfuric acid. The molar enthalpy for Magnesium should only vary because of human error. ...read more.


Ideally the three molar enthalpies should be the same, because the molar enthalpy for magnesium is dependant upon magnesium, not the other reactant. (In Ethanoic acid: 2.8E2 kJ/mol, In Sulfuric acid: 3.5E2 kJ/mol, In Hydrochloric acid: 3.5E2 kJ/Mol) Q: How does the rate of reaction of magnesium vary with these acids? A: The rate of reaction varies noticeably in the three acids. The rate was fastest in Sulfuric acid, at 5.29E-5 mol/s, second fastest in Hydrochloric acid at 1.87E-5 mol/s, and slowest in Ethanoic acid at 7.61E-6 mol/s. Since the surface area of the magnesium and the temperature of the acid was essentially the same in every sample, the only reason that the rates would vary this much is due to their different chemical properties. Evaluation As predicted before the experiment, there was a lot of fizzing and bubbling during the reaction. Also, as predicted, the system increased in temperature in all segments of the experiment, due to the exothermic nature of the reaction. Contrary to the hypothesis, the Carboxylic acid had the slowest rate of reaction with magnesium. This could be due to the slight polarity of Ethanoic acid. ...read more.


A way to control the exothermic nature of this reaction would be cooling it down as the reaction goes on. Adding more Freon or ice to the surrounding atmosphere to absorb the heat given off by the reaction. Not enough to cool down the solution, just enough to keep it at a stable temperature. Something like this would be effective in providing heat in a hand warmer, but for multiple reasons, unsafe. In order to generate enough heat to keep somebody's hands warm in the winter, the acid would have to be pretty concentrated. This concentrated acid would be a hazard to the person if it ever leaked, caustic acid can cause irritation to skin and in some cases severe burns. Also there is a considerable amount of hydrogen gas produced in this reaction, which needs to go somewhere. The package with the acid and Magnesium in it would have to have ventilation for the gas to escape. This would be a place for the acid to leak out also. Acid and magnesium is not the ideal exothermic reaction to provide heat for hand warmers due to the risk of acid burns. Calculations 1 Unit 3 Lab: Lab 3: Energy and Rates Analysis of Chemical Reactions ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our AS and A Level Inorganic 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 AS and A Level Inorganic Chemistry essays

  1. Peer reviewed

    Determining the concentration of acid in a given solution

    5 star(s)

    needed to reach the rough end point * Fill up the burette again so that there is plenty of solution for the next titre * Read the value to the nearest 0.05cm3 and record it on the paper * Get a new conical flask and rinse it to ensure it

  2. effects Concentration and Temperature on the Rate of Reaction

    x (RFM of chemical) x (desired amount of solution/ml) 1000ml For example, to make 100 ml of 0.1M X2Y3 solution, you would work out how many grams of X2Y3 to use as is shown below: grams of X2Y3 = [0.1 x (2n3m)

  1. Lab report Determination of Enthalpy Change of Neutralization

    So, No of mole of H2O = 0.1 mol Heat given out per mole of H2O formed = 6419.260504/ 0.1 = 64.2 KJ mol-1 The enthalpy change of neutralization is -64.2 KJ mol-1 Reaction 6: Mass of the solution = (25 + 25)

  2. The preparation, analysis, and reactions of an ethanedioate complex of iron

    When the solution was heated to 70?, the thermometer was removed and washed down, and was titrated with the standard, approximately 0.02M solution of permanganate. A pink color was persisting for 30 seconds at the end-point. The resulting solution was kept for the determination of iron in (b).

  1. Finding Out how much Acid there is in a Solution

    in eye: flood eye with water for at least 10 minutes, seek medical advice * Sulphuric Acid (H2SO4) o Corrosive at higher concentrations, but irritant if below 0.5 mol dm-3 o Spilt in laboratory: wash area with water o Spilt on skin: rinse affected area with plentiful water o Spilt

  2. The Effects of Strong and Weak Acids on the Order of a Reaction.

    Figure 3: http://www.docbrown.info/page03/3_31rates.htm#3a Effect of temperature As stated previously, every particle has some energy within them - this is called Kinetic energy. As the temperature is increased, the kinetic energy these particles have is also increased. This means that the particles are not only moving faster - which will help

  1. Determination of Chemical Oxygen Demand (COD) of a Given Sample of Waste Water

    K2Cr2O7 reacts with organic matter during reflux as the following equation Cr2O72- + 8 H+ � 2Cr3+ + 4H2O +3O Organic matter is being oxidised. mole ratio of Cr2O72- : O = 1:3 molecular weight of oxygen= 16gmol-1 Weight of oxygen generated = 3 x 16g = 48g As volume

  2. The purpose of this experiment was to prepare a sample of Aspirin and measure ...

    As it is very tricky to get exactly 50g of the acid exactly the sample used was 50.07g, as close as possible to the preferred amount. In addition to these two reactants a maximum of 0.5ml of concentrated sulphuric acid was added to the flask.

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