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

I aim to investigate the rate and mechanisms of the reactions between magnesium and acids.

Extracts from this document...


PLANNING Aim I aim to investigate the rate and mechanisms of the reactions between magnesium and acids. Introduction The reactions I will investigate are nitric acid with magnesium, and sulphuric acid with magnesium. I will vary the concentration of nitric and sulphuric acid in separate experiments, and I will vary temperature in order to study what effect these variables have on the rate of reaction. The mass of magnesium used will remain constant. My experience in chemistry suggests that the rate will increase with both concentration of acid and temperature, the exact relationships will be investigated. The variation of rate can be described by the rate equation, specific for each reaction. The rate equation must be found by experiment rather than predicted by theory, it takes the form: Rate = k[A]x[B]y where the square brackets indicate the concentration of the substance indicated inside them, the x and y indicate a power that this concentration is raised to and k is the rate coefficient. The rate coefficient is constant at a constant temperature, and its variation with temperature is described by the Arrhenius equation: k=Ae(-E/RT) where E is the activation enthalpy, R is the molar gas constant, T is the temperature and A is a constant. ...read more.


Note that the sodium hydroxide was added rapidly as soon as the time period had elapsed. This whole process was then repeated with different concentrations of nitric acid, all other variables are constant. The nitric acid was diluted from its original 2M by the table below. The entire process was then repeated with sulphuric acid in place of nitric acid. Then the whole experiment was repeated at 50�C. This was achieved by placing all reactants; acid, sodium hydroxide and magnesium in separate boiling tubes and submersing them in a water bath set at 50�C. There they were left to heat for five minutes, and then the acid added to the magnesium and the boiling tube placed back in the water bath. The titration was performed as before. Dilution Table Start with 2M nitric or sulphuric acid, depending on experiment. Always make up to 20cm3. Water used is distilled water. 2 M 20cm3 acid 1 M 10cm3 acid, 10cm3 water 1.75 M 17.5cm3 acid, 2.5cm3 water 0.75 M 7.5cm3 acid, 12.5cm3 water 1.5 M 15cm3 acid, 5cm3 water 0.5 M 5cm3 acid, 15cm3 water 1.25 M 12.5cm3 acid, 7.5cm3 water 0.25 M 2.5cm3 acid, 17.5cm3 water Risk Assessment Clearly I will be dealing with strong concentrated acids and alkalis and so care must be taken not to allow contact with skin or eyes. ...read more.


Fewer, in fact half, as many moles of sulphuric acid will react with the same amount of magnesium as nitric acid, due to the ratios of the reactions below: Mg + 2HNO3 ==> Mg(NO3)2 +H2 Mg + H2SO4 ==> MgSO4 +H2 HNO3 + NaOH ==> NaNO3 + H2O H2SO4 +2NaOH ==> Na2SO4 +2H2O EVALUATION Sources of Error The 10cm3 measuring cylinders used to measure out the volumes of acid and base were accurate to �0.1cm3. The burette used in the titration was accurate to �0.05 cm3. There is human error involved in judging the end-point of the titration, though I chose methyl red as my indicator as it gives a very clear colour change and was very careful in my method it is possible that I did not measure the exact end-point. It is also likely that such an error would not be systematic and so could affect the results randomly. Improvements If I were to perform this investigation again with unlimited resources, I would first use larger quantities of all reactants in order to reduce possible error and to make conclusions firmer. I would investigate a wider range of acids, acid concentrations and temperatures in order to draw firmer conclusions about the trends and relationships I have identified. 1 Page ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our GCSE Aqueous 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 GCSE Aqueous Chemistry essays

  1. Marked by a teacher

    To investigate the effect of temperature on the rate of reaction

    4 star(s)

    Temperature (�C) 70 60 50 40 30 20 10 0 time intervals (s) 1st 2nd 3rd av. 1st 2nd 3rd av. 1st 2nd 3rd av. 1st 2nd 3rd av. 1st 2nd 3rd av. 1st 2nd 3rd av. 1st 2nd 3rd av.

  2. Science Investigation Report - Aim To investigate how the voltage of the electric ...

    This is measured through subtracting the final mass of the electroplated paper clip from the initial mass of the paper clip before electroplating, with units in g. Controlled Variables: --> Time taken for electroplating - The time taken for the paper clip to be electroplated should remain the same, as

  1. Determine the Enthalpy of Neutralisation for the following there Acids, H2SO4, HNO3 and H2SO4

    x 6.2�C = 1302.00 J Moles of HNO3= volume (dm3) x concentration (moldm-3) = 25/1000 x 0.5 = 0.0125 moles Unlike the other acids, the molar ratio of H2SO4 with NaOh is 1:2, shown by the following neutralisation reaction H2SO4 + 2NaOH --> Na2SO4 + 2H2O Therefore the no.

  2. The rate of reaction between magnesium and sulphuric acid.

    Amount of H? 30 46 4 cm3 60 39.5 10.5 cm3 90 33 17 cm3 120 28.5 21.5 cm3 150 24.3 25.7 cm3 180 22.3 27.7 cm3 13ml of Acid: 7ml of Water Time measured in seconds Reading on burette (ml)

  1. To investigate the differences in order of reaction and activation energy of the reactions ...

    of the reaction in respect to the acid and compare the effect of changing the strength of the acid from weak to strong.) The order of reaction can be shown in a graph of rate against concentration the orders zero, 1st and 2nd have the following characteristic shapes: zero order:

  2. In order to find out the exact concentration of sulphuric acid, I will have ...

    be got rid off, otherwise the concentration of new solution might have been contaminated by the previous one. I also made sure that all readings of menisci were taken at eye-level, in order to avoid any possible parallax error. As I previously stated sulphuric acid is a strong base while sodium carbonate is a weak acid.

  1. See how different concentrations of Hydrochloric acid change the rate of reaction with a ...

    Measure out 3cm� of 0.5M hydrochloric acid using the measuring cylinder 4. Pour the hydrochloric acid into the test tube 5. Measure 1.5cm of magnesium ribbon. 6. Drop the magnesium into the test tube 7. Start the stopwatch 8. Stop the stopwatch once the magnesium has fully reacted and record the time.

  2. The aim of this experiment is to answer the following question: What is the ...

    I will do this by dissolving one mole of Caustic soda crystals into one litre of distilled water. One mole of Sodium Hydroxide: Na = 23 O = 16 H = 1 Total = 40 x 0.4 moles = 16g Therefore I will dissolve 16g of sodium Hydroxide in one litre of distilled water.

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