• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month
  1. 1
  2. 2
  3. 3
  4. 4
  5. 5
  6. 6
  7. 7
  8. 8
  9. 9
  10. 10
  11. 11
  12. 12
  13. 13

The effect of temperature on the rate of reaction

Extracts from this document...


Simon Flood Mr Macintosh 11C Chemistry Course work 11Hawking School Number: 37625 Candidate number: Investigation: The effect of temperature on the rate of reaction We are conducting an experiment to ascertain whether Magnesium strips will dissolve quicker in a solution of Sulphuric Acid at various temperatures. During the experiment I am trying to find out whether temperature will have an effect on the rate of a reaction, and also what the effect on the reaction is. Throughout the experiment I shall test the following reaction: Magnesium + Sulphuric Acid ? Magnesium Sulphate + Hydrogen Mg (s) H2 (aq) MgSO4 (aq) H2 (g) Preliminary Test: Before starting our experiment we had to think ahead to any problems we may encounter during the experiment in and what would be the best way to resolve them. There were three main areas we decided it would be necessary to test, and these are listed below along with how we have decided to resolve them: * Exothermic Reaction: The majority of reactions give off excess heat, which basically means they are exothermic, and this would affect the results of our experiment as we are testing how temperature change can effect the rate of reaction. Basically this shows us that we need to find the activation energy. Activation energy is the minimum amount of energy put into the reaction to get the minimum out of it. Reactants have an amount of energy. You need to put the same amount of energy in to get the Activation energy. Following is a table showing how different concentrations of sulphuric acid and lengths magnesium strip affect the temperature: Mg strip(cm) Temp before(oc) Temp after (oc) Time of reaction (s) Vol. Acid(cm3) 0.5 20.0 22.0 39.91 30.0 1.0 20.0 21.0 41 40.0 1.5 20.0 22.0 69.91 20.0 Previously we knew that the rate of a reaction will change during the reaction. It is greatest at the start, but declines as the reaction proceeds because reactants are being used up. ...read more.


In our case dilute acid is the concentration and there are fewer acid particles, therefore there are less collisions between acid particles and magnesium atoms and therefore the reaction takes longer. - Size of Solid Particles (Surface area) increases collisions: If one reactant is a solid then obviously breaking it up will split these solid particles up again increasing collisions due to them being bigger. The greater the surface area, then the faster the rate of reaction will be, in the smaller particles the entire surface exposed for reaction is greater therefore more collisions occur and due to the increase in collisions, the rate of reaction is obviously going to be faster. - Catalyst increases the number of collisions: A catalyst works by giving the particles an extra surface to bounce off of and again increasing collisions. Catalysts offer an alternative path with a lower activation energy. Before reactants are able to convert into products, they must overcome an energy barrier. This is the slowest part of the reaction. The energy needed for a reactant to overcome the energy barrier is called the activation energy. Effectively, a catalyst lowers the activation energy, therefore speeding up the reaction (ie, the reaction rate increases). Nb: a catalyst is a substance that changes the rate of a reaction, but remains chemically unchanged itself. The Boltzmann theory relatively fits in with my predictions/scientific evidence, therefore I shall include it below: We can now look at the Boltzmann theory graph: - I have found looking at the GCSE double award Chemistry revision guide the Maxwell Boltzmann distribution. Looking at the Boltzmann Distribution we can see that an increase in temperature increases the rate of reaction. Below is the diagram: We can see this by the fact that: -Molecules in larger numbers exceed the activation energy. -The faster the molecules travel the more frequent the collisions are. -The Boltzmann distribution curve is displaced with a lower peak to the right increasing the average energy. ...read more.


Further Work To improve my results further, I could repeat the experiment three or four times and find the average, rather than only repeating the experiment once and finding averages of the minor experiments within this larger one. Factors that I know, but did not take into account in this experiment, are that - (1)The reaction between magnesium and hydrochloric acid is an exothermic one (which I found out by placing a thermometer in the mixture during the reaction and observing that the level in the thermometer had increased) - (2)The reaction gives off a high percentage of hydrogen gas (this is due to the fact that when the magnesium reacts with hydrochloric acid, it displaces the hydrogen from the acid, as it is placed higher than Hydrogen in the reactivity series). The problem with (1) is that, due to the reaction being exothermic, the reacting particles will gain more energy from the increasing temperature and thereby reach the required activation energy in a shorter time. This could increase the rate of reaction and lead to inaccurate results. I could investigate a method for keeping the reactants at a constant temperature. Taking (2) into consideration, I could repeat this experiment, this time recording the amount of hydrogen gas given off from each concentration of acid. I could use a gas syringe to collect the gas that would be given off from the experiment between the two substances. I believe this is a better way to investigate the rate of reaction(on temperature) as it would be possible using these results only, to calculate the initial rate of reaction. Thus could prove to be a more accurate set of results rather than averaging the rate of the reaction after the actual experiment, as I would then know the real/actual rate of reaction for magnesium and hydrochloric acid combined. Investigating the reaction of Magnesium with different types of acid each time could further enhance the investigation. Hydrochloric, Sulphuric and Nitric acid would all react differently and perhaps give a greater understanding into the reaction mechanism with a clear pattern linking them all together. ...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 Patterns of Behaviour 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 Patterns of Behaviour essays

  1. Marked by a teacher

    The effect of concentration on the rate of reaction of Magnesium with Sulphuric Acid.

    3 star(s)

    Repeat the above steps for each concentration of sulphuric acid (0.2, 0.4, 0.6, 0.8, or 1mol/dm�) Strategy for Results To record my results I collected in my experiment, I will use a table that will look like this: Concentration of acid Time (sec)

  2. Marked by a teacher

    How dose temperature affect the rate of reaction between magnesium and hydrochloric acid.

    3 star(s)

    The repeat number 1 for starting temperature f 25�C is the anonymous result. I also drew a graph to represent this data (see next page). On it I plotted the rate of reaction at different temperatures. Temperature is a controlled variable, so it is measured up the x-axis and rate

  1. Marked by a teacher

    For my experiment I am finding out the effects on the reaction rate when ...

    3 star(s)

    cause irritation if in contact with skin and could burn through clothing, are visible. Also wear goggles so that chemicals do not get in contact with your eyes which could potentially blind a person. The easier and safer option is to wear gloves.

  2. Free essay

    Close Your Eyes

    "What now?" she asked impatiently. "Well, nothing really its just that I thought you said you were gonna behave yourself tonight." I smiled at her. She didn't look impressed but then she broke into a smile. "Daniel Jones....shut up and take your clothes off!"

  1. To investigate the effect of the concentration of nitric acid on the rate of ...

    length of time, and record how much gas has been produced from the reaction at certain time intervals. VARIABLES AND COLLISION THEORY: There are four main factors or variables which influence the rate of a reaction, and they are: 1. TEMPERATURE 2. CONCENTRATION (or pressure for gases) 3. CATALYST 4.

  2. Investigate various ways of increasing the rate of a chemical reaction and evaluate which ...

    However, in a reaction where the product is in a different state, the time taken for a reactant to be used up or the time taken for the product to be formed may be measured relatively easily. There are several main ways that this can be done.

  1. Rates of reactivity.

    * The chippings were taken and gently poured into the acid in the conical flask and simultaneously the stopwatch was started. * Immediately the cotton wool was placed on the neck of the conical flask. * This should be done in as short a space of time as possible.

  2. An Experiment to Investigate the Factors which effect the Rate of Reaction between Magnesium ...

    Results Here are the results I obtained from carrying out my experiment, as I stated in the method. I did not change my method, to achieve these results. 100% acid 80% acid 60% acid 40% acid Time (secs) Amount of hydrogen produced (cm�) Time (secs) Amount of hydrogen produced (cm�)

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