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

An Investigation into the Heat of Neutralisation

Extracts from this document...

Introduction

An Investigation into the Heat of Neutralisation Planning: Aim: the aim of this investigation is to look at what effect concentration has on the temperature and energy changes in a neutralisation reaction. Introduction: Neutralisation occurs when an acid and an alkali base are reacted together to form a neutral solution. Despite this, a neutral solution will only be achieved if the alkali and acid are of equal strength. This occurs because the H+ ion in the acid reacts with the OH� ion in the alkali to form H20 or water, which is neutral. The H+ ions are destroyed when they are reacted with a carbonate or metal base. The OH� ions are destroyed when they are reacted with an acid. The equation for this is shown as follows: H+ + OH� H20 However alkalis and acids all differ because of their structure. This means that as well as water being produced, so is a salt. Acid + Alkali Salt + Water XH+ + YOH� XY + H20 HCl + NaOH NaCl + H20 Neutralisation is always an exothermic reaction, therefore heat is given out, because the energy released from forming bonds is greater then that taken in and used in the breaking of the bonds. ...read more.

Middle

4. Record the temperature of the alkali. 5. Measure out 25cm3 of HCl using the second measuring cylinder and pipette. 6. Record the temperature of the acid. 7. Pour the acid into the cup along with the NaOH and very quickly place on the lid. 8. Stir the solution five times with the thermometer. 9. Wait until the temperature has reached its highest point, i.e. when there are no signs it will increase, and then record it. 10. Wash out the measuring cylinders, thermometer and cup then repeat the experiment twice more. 11. Repeat the whole experiment to obtain results for the different combinations of acids and alkalis shown above. When completing the results table below, the initial temperature is the average of the initial temperature of acid and that of the alkali. Results: HCl (hydrochloric acid) CH3COOH ( ethanoic acid) CH3CH2COOH (propanoic acid) NaOH (sodium hydroxide) Initial temp 0C Final temp 0C Temp change 0C 1 2 3 1 2 3 1 2 3 22.1 22.2 22.3 23.4 23.3 23.9 25.1 23.8 23.5 28.8 28.8 28.9 29.7 29.4 30.3 31.3 28.3 27.9 6.9 7.0 7.0 6.3 6.1 6.4 6.2 6.5 6.4 NH4OH (ammonia solution) ...read more.

Conclusion

Although heat was lost to the surroundings, it was lost in all my experiments equally. If I were to redo the experiment there are a few improvements I would make. I feel that I could have been more accurate in measuring my volumes of acid and alkali, but then flaws in my readings could be attributed to human error. Also, because of human error the readings on the thermometer may not have been accurate, however, using a thermometer connected to a computer and having the computer take the readings could solve this problem. Repeating my experiment another time for each of the reactions would be more accurate as I would have more data. If repeating the experiment I would insulate the lid of the cup and the measuring cylinders to prevent heat loss through them. To extend the investigation I could also look at some of the variables that I mentioned above. If I were to investigate a wider range of acids and alkalis it would extend the investigation and enhance my results. Another extension would be to experiment with different concentrations and seeing how they affect the heat of neutralisation, however this was not possible due to time limitations. Laura Davies Chemistry Coursework ...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 determine the amount of ammonia in a sample of household cleaning product, 'cloudy ...

    5 star(s)

    The HCl acid was titrated with the ammonia sample until the indicator change from yellow to 'salmon pink' (end point). The volume of HCl used was recorded in Table 3.2. 6. Steps 4-5 were repeated until two or three of the data obtained were within 0.1ml of each other.

  2. Marked by a teacher

    Chemistry Investigation on neutralisation reaction.

    5 star(s)

    This reaction is exothermic and gives out heat. This temperature rises. If you add a little bit of acid at a time to a known volume and concentration of alkali, I can plot a graph of temperature rise against volume of acid added. At some point, the temperature no longer rises as all the alkali OH- has neutralised the H+ ions of acid.

  1. Marked by a teacher

    Enthalpy of Neutralisation.

    3 star(s)

    ? H2O ?H ? n,m (298 K) = -57.1 kJ mol-1 Thus, an exothermic reaction is taking place. However, this is different for ethanoic acid because it is a weak acid and does not fully dissociate in water (therefore there will be no complete reaction) compared to the strong acids, which dissociate in water.

  2. Investigate a neutralisation reaction between hydrochloric acid and sodium hydroxide.

    From this book I obtained some relevant information that will help me plan my investigation. I also did preliminary work to see what changes I had to make to my plan in order to have the best plan as possible.

  1. Investigation to find out the factors affecting heat of neutralisation, and then choosing one ...

    I am going to look at the various energy changes when reacting a strong alkali with a strong acid, a strong alkali with two different weak acids, a weak alkali with a strong acid and a weak alkali with two different weak acids.

  2. Analysing the ethanoic acid concentration in different types of vinegars.

    Quantitative Errors are due to the limitations of the equipment that I have used, and therefore if I know the accuracy of my equipment I can work out the maximum percentage effect quantitative error could have had on my results.

  1. To investigate the effect of concentration on the temperature rise, heat evolved and heat ...

    ?T = Q / (m x c) ?H = Q / moles I will use direct proportion rule to predict the amount of heat that should be evolved for each reaction after finding the number of moles of NaOH used in the reaction by using the formula I stated before.

  2. Antacid Investigation.

    It also was not accurate because when the results are being read they are not exact they would not be exact because it will be very hard to read the burette accurately using the naked eye, although this would have not made a large change.

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