• 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 variables that effect energy changes during a neutralisation reaction.

Extracts from this document...

Introduction

Nazreen Deller Chemistry Coursework 12/10/02 Aim : An investigation into the variables that effect energy changes during a neutralisation reaction. Background information : A neutralisation reaction is a process whereby the acidity or alkalinity of a substance is destroyed. In order to make a neutral substance you must first determine the ph of the substance, one you have determined whether it is alkali or acid you can then add the same mount of alkali if the substance is acid. This will remove H+ (aq) ions. If the substance is an alkali then you must add the same amount of acid, removing the OH- (aq) ions. It is important that the acid and alkali particles are exactly equal to get a neutral solution. When two chemicals are neutralised, a reaction occurs. This reaction normally results in an event called 'energy change'. An energy change is normally the discharge of energy lost in a reaction. There are two types of energy change If a bond is broken during a reaction, energy is needed , so the surroundings lose heat and reactants gain energy in the form of heat to carry out this action this is carried out through an Endothermic energy change. ...read more.

Middle

The equation of this reaction is : HCl (aq) + NaOH (aq) NaCl (aq) + H2O (l) Examples of Neutralisation in everyday life. * Bee sting : This is acidic. It can be neutralised by bicarbonate of soda. * Wasp sting : Unlike the bee sting this is alkaline and can be neutralised by vinegar. * Indigestion : when there is too much acid build up in the stomach. It can be neutralised by an alkaline tablet. Apparatus : * 2 Burettes * 2 Stand and clamp * Funnel * 2 Beakers * Hydrochloric acid * Sodium hydroxide * Distilled water * Universal indicator * Materials and lids for insulation (lids with holes in to fit a thermometer.) * Thermometer. Variables : We will carry out the experiment 6 times with different concentrations of the reactants which are hydrochloric acid and distilled water. Safety: * Safety goggles must be worn when using chemicals and at all times during the experiment. * If any of the chemicals come in contact with skin or clothing it should be rinsed of immediately as they can be irritant or corrosive. ...read more.

Conclusion

Prediction : I predict that the more water and less acid is introduced into the solution will make it weaker and I think that this will slow down the reaction and it will cause less rise in heat. Results Table : Hydrochloric Acid (ml) Distilled Water (ml) Sodium Hydroxide (ml) Temperature Before (degrees C) Temperature After (degrees C) Difference (degrees C) 25 0 25 19 28 9 20 5 25 18 27 9 15 10 25 17 25 8 10 15 25 16 23 7 5 20 25 16 20 4 0 25 25 15 17 2 Conclusion: As less acid and more water is introduced to the sodium hydroxide the temperature decreases as does the difference in temperature. When a solution is neutralised it takes part in an endothermic energy change, this means that the solution gives out heat if the reaction is more violent then there will be more heat produced. The results as I predicted should go down in temperature as the hydrochloric acid is decreased and the water is increased. Evaluation: My results have been conclusive to scientific evidence and my prediction. If I could re- do the experiment I would use better insulation and better measuring equipment. ...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)

    Polystyrene cup Method For the first experiment I will pipette 25cm3 of sodium hydroxide of 2 moles/dm3 into the polystyrene cup. I will measure the temperature of the sodium hydroxide in the polystyrene cup. I will then from the burette run in 5cm3 of hydrochloric acid whilst stirring the solution with a stirring rod.

  2. Marked by a teacher

    Investigating The Energy Change During A Neutralisation Reaction.

    4 star(s)

    Acids react with metals, which are above Copper in the reactivity series, to form a metal and a salt. Acids react with carbonates to give a salt, carbon dioxide and water. Acid solutions also conduct electricity, but are also decomposed by it, this shows that the acids consist of ions,

  1. Marked by a teacher

    Enthalpy of Neutralisation.

    3 star(s)

    The surroundings will necessarily gain whatever heat the reacting materials lose, and vice-versa. Thus, the total energy is unchanged during a chemical reaction. Energy may be exchanged between the materials and the surroundings but the total energy of the materials remain constant.

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

    This goes on to prove that the heat evolved directly varies along with concentration. This is because when the concentration increases the reacting particles increase and when this increase more reactions happen and when this happens more heat is given out.

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

    It is known that the breaking of bonds causes energy to be taken in, and when bonds are made, energy is given out. Another reason for a stronger acid producing a higher value for the heat of neutralisation is because it has more free H+ ions.

  2. 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.

  1. Investigation into the efficiency of various indigestion tablets.

    = 0.1135 x 4.907 = 0.5569445 g (times more) = 556.9 mg CaCO3 Amount of CaCO3 in Rennie CaCO3 + 2HCl --> CaCl2 + CO2 + H2O nHCl = v x c = 0.0282 x 0.1 = 0.00282mol (dm3) (M HCl)

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

    A thermometer is used to measure the temperature to help me find out weather the reaction is exothermic or endothermic. Apparatus list ? Polythene cup ? Measuring cylinder ? Beaker ? Thermometer ? Stopwatch Diagram Hydrochloric acid and Sodium hydroxide Thermometer Stopwatch Polythene cup The apparatus will be collected and set up as indicated form the diagram.

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