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

Energy conversion in a neutralisation reaction

Extracts from this document...

Introduction

Energy conversion in a neutralisation reaction Aim We are trying to find out what factors affect the energy conversion in a neutralisation reaction. Variables The variables that can be changed are Concentration of acid Type of Acid Concentration of alkali We choose type of acid Prediction I predict that if the acid is stronger (has a lower pH) than more heat will be given out in the endothermic reaction. Theory Strong and Weak Acids- Acid is an H+donor and a consequence of this is that, in aqueous solutions, acid donates H+ to water molecules to produce oxonium ions H3O+. The presence of oxonium ions gives rise to the familiar acidic properties of all aqueous solutions of acids. Acids vary in strength. Different acids donate H+ to differing extents. Strong acids have a strong tendency to donate H+: the donation of H+ is essentially complete. The reaction with water can be regarded as going to completion and can be described by the following equation, where HA represents the strong acid. ...read more.

Middle

We then put some universal indicator in each beaker and recorded the pH. Then we put a thermometer in one of the beakers with sodium hydroxide in it and added 25 ml of acid to it. Then we observed the thermometer until the maximum the temperature was reached and noted down the result and also noted down the new pH. We then did this two more times for the same acid, after which we changed the acid and did the same for the new acid. We did this for each of the five acids, with two repeats for each acid. Throughout the experiment we wore safety spectacles. Results Acid Starting Temperature (oC) Ending Temperature (oC) Repeat Repeat 1 2 3 1 2 3 Hydrochloric Acid 21.0 20.5 19.8 32.9 32.5 32.4 Sulphuric Acid 21.0 21.0 20.9 32.4 32.8 32.8 Nitric Acid 20.5 21.0 20.8 31.2 32.0 31.5 Acetic Acid 20.9 20.8 20.8 29.9 30.0 29.6 Phosphoric Acid 20.5 21.0 20.8 29.9 30.5 30.1 Acid Average Starting Temperature (oC) ...read more.

Conclusion

It would be impossible to record to over one decimal place; even one decimal place is a slight estimate. Also it was hard to know when the maximum temperature would arise. You had to watch until the temperature started going down and the record the maximum temperature. Even though the results would not wholly accurate, the results came out as expected and agree perfectly with scientific theory so think this is evidence enough to make a firm conclusion that the lower the pH of an acid, the greater the energy conversion in a neutralisation reaction. If I were to do a further investigation it would be to find out if the same applies to alkalis in a neutralisation reaction. So, if the alkali in the reaction has a higher pH, the energy conversation is greater. To do this I would do the experiment the same, except I would choose an acid to keep the same though preliminary work and vary the alkali, instead of the acid. My prediction would be that as the pH of the alkali increased, the energy conversation would increase. ...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

    Chemistry Investigation on neutralisation reaction.

    5 star(s)

    The stronger the concentration of the acid, the more acid molecules will be in any particular part of the solution. Therefore it is more likely that they will bump into the alkali molecules, cause more reactions to happen and more heat released to measure.

  2. Marked by a teacher

    Investigating The Energy Change During A Neutralisation Reaction.

    4 star(s)

    Neautralisation reactions are usually exothermic. Acids are compounds of non-metals with simple molecular structure. They all contain hydrogen (H) covalently bonded to other elements. Acids are also soluble in water and produce solutions with a pH of less 7. They will turn litmus paper red and turn universal indicator an orange/red colour.

  1. Marked by a teacher

    Enthalpy of Neutralisation.

    3 star(s)

    Consequently, ?H ?298 values for reactions involving carbon should relate to the allotrope graphite rather than diamond. We can therefore define the standard enthalpy change of a reaction as the amount of heat absorbed or evolved when the molar quantities of reactants a stated in the equation react together under certain conditions.

  2. Investigating the factors the affect the heat change in a neutralisation reaction.

    takes the place of the Hydrogen in the acid, forming a metal compound called a salt. The term salt is used to describe any compound formed by the reaction between a base and an acid. From the above equation, we can break up these molecules into this: Na+(aq) + OH-(aq)

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

    (negative oxygen ions) ions to form water. This is a neutralisation reaction. Acid + Alkali ? Salt + Water Hcl + Naoh ? Nacl + H20 To from a salt the Na + ions must bond with Cl? . Na + + Cl? ? Nacl To from water H + ions must bond with the 02? ions.

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

    /3 = -46.5 KJmol-1 For HCl and ammonia solution, heat of neutaralisation= -(MC /1000/ 0.03) =1. - ( 60 * 4.2 * 6.5 /1000 / 0.03) 2. - (60 * 4.2 * 6.4 / 1000 / 0.03) 3. - (60 * 4.2 * 6.4 / 1000 / 0.03) = 1.

  1. To investigate the factors that affect the amount energy produced in neutralisation reactions.

    When reacting both acid and alkali, both quantities must be as equal as possible, if a neutral solution is desired. Strong acids and strong bases completely break up, or dissociate, into their constituent ions when they dissolve in water. In the case of hydrochloric acid, hydrogen ions, H+, and chloride ions, Cl-, are formed.

  2. Energy Change Associated With Neutralisation

    This will cause the temperature of the end product to rise. In my investigation when the acid + base react together they will not require as much energy to form the products as the amount of energy they have already stored inside them.

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