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

Thermometric Titration Investigation

Extracts from this document...

Introduction

Thermometric Titration Investigation Sam Murphy 11T Planning We have to plan an experiment which measures the temperature change accompanying neutralisation so that it can be investigated. Neutralisation is when an acid and an alkali mixed together neutralise the other. The hydrogen and the hydroxide ions bond to form water and the rest bonds to form a salt. For example in the case of hydrochloric acid and sodium hydroxide, the salt is sodium chloride. Neutralisation is an exothermic reaction, like all reactions where bonds are formed. I plan to measure this heat energy released by the reaction (although it is possible to do the same for endothermic reactions, those that take heat energy from their surroundings rather than release). Neutralisation; Word Equation: Alkali + Acid = Salt + Water EXAMPLE: Sodium Hydroxide + Hydrochloric acid = Sodium Chloride + Water With titration equipment, I plan to add acid to an alkali (sodium hydroxide) until it is neutralised, Measuring the temperature so that I can work out the ? H. This means, I will add bit-by-bit, acid to the alkali in set amounts (3 ml) at a time. Measuring the temperature after adding the acid to the alkali. We will measure the change in Heat Energy by using this equation to work out the "? H" (Change in heat energy). For accuracy sake we will repeat the experiment for each acid so that we have two sets of results from each to work out a mean average. ...read more.

Middle

which means approximately equal amounts of each will create a neutral solution 4. Add the HCL to the NaOH, 3cm3 at a time. 5. After you have added some acid, stir the Polypot with the thermometer and quickly record the temperature and move on 6. Carry on until the change in temperature is small and several negative temperature change results are recorded, indicating the alkali has been neutralised Safety: * The acids that will be used are 2 molar, twice as strong as the usual strength used, this makes it far more important to use goggles and not to spill on clothes or you. * Check carefully to see if the burette is secure, if it isn't then it may fall and break, this would result in acid and glass shards on the desk and floor, not safe for reasons too obvious to mention. * Make sure the burette doesn't leak or drip. * You should always be standing during an experiment, but in this case, with stronger corrosive solutions, this becomes even more important. * This may not have much to do with the experiment, but while carrying the acids and alkalis around, remember to watch out for bags and stools or any obstacles which may cause you to trip up. * The thermometers we use contain mercury which is poisonous, but also, so is the vapour, so any fabric or other thing which soaks it up must be washed because it could give you poisoning, especially clothes. ...read more.

Conclusion

But it was all surprisingly accurate, the doubled results were all close together so that the fact they were not greatly different shows that they were either both wrong (unlikely) or most likely, both about right. Not being more precise than a millilitre when your dealing with three millilitres is bound to cause problems, same with a small range of temperatures. Altogether, taking into account: 1. Measuring to millilitres 2. Measuring to degrees C (not decimal places) 3. Dilution due to pipette / burette 4. Heat Loss 5. Human error on the burette tap (time and amount) 6. The specific heat capacity being a bit different 7. Splashing caused by stirring, reduces amount in pot Altogether it is about 10% accurate, considering some inaccuracies work against each other, like 4 and 6, using a lower specific heat capacity than you really have creates heat whereas 4 is about actually losing it. The graph was mostly accurate, and it showed up only one anomaly, though I have no explanation for it. Ideally, I would have a thicker poly pot with a lid. A magnetic stirrer would mix it, an electronic probe measuring to 2 decimal places stuck in the lid (same for the end of the burette) and a stop-clock to measure the interval of 20-30 seconds between adding the acid. Obvious further work would be trying out different combinations of acids and alkalis, but, you can also measure heat produced in other exothermic reactions, or try measuring the heat used by endothermic reactions. ...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

Here's what a teacher thought of this essay

4 star(s)

****
A good account of the investigation with useful background information. The author might have discussed variables in more detail and a bit of double checking should have avoided getting the specific heat capacity of water wrong.

Marked by teacher Adam Roberts 14/10/2013

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

    ANALYSIS OF ASPIRIN BY BACK TITRATION

    4 star(s)

    moles NaOH It was then possible to calculate the number of moles of aspirin that has been reacted. The answer was then compared to the manufactures label stating the aspirin content. It was also found that there was 297 mg of aspirin in the aspirin tablets compared to the 300 mg stated dose on the label.

  2. A thermometric titration - determine the concentrations of hydrochloric acid and ethanoic acids by ...

    Moreover, we must replace the lid before stirring which can minimize the heat lost to the surrounding. We should stir gently or the plactic lid will break as a result of our volience. After all, after the experiment we will plot a graph to determine the highest temperature, it is

  1. Indigestion Tablets Investigation

    Prior to conducting this investigation I went into a Boots Pharmacy and found that the tablets contain the following active ingredients > Calcium Carbonate (PhEur 200mg) > Magnesium Carbonate (PhEur 200mg) > Magnesium Trisilicate (PhEur 60mg) > Sodium Bicarbonate (PhEur 60mg)

  2. Acid-Base titration of Sulphuric acid and Sodium Hydroxide

    DEPENDENT VARIABLE The dependent variable in this experiment is the volume of sulphuric acid from the burette that was used to neutralize the base.

  1. To prepare antifebrin using phenylammonium chloride C6H5NH3CL and Ethanoic anhydride (CH3CO)2O.

    + (CH3CO)2O CH3CONHC6H5 + CH3COOH + HCL Molar ratio: 1 : 1 The molar mass of Phenylammonium chloride (C6H5NH3CL) is: 129.5 g mol-1 The amount of Phenylammonium chloride used 1.0g Therefore the moles of Phenylammonium chloride is calculated using: Mass = 1__ = 0.00722 mol-1 Molar mass 129.5 1 mol of Phenylammonium chloride gives 1 mol of antifebrin.

  2. Determine Solubility of KClO3 Salt.

    Gases Formula Solubility g/100-mL Temperature /K Ammonia NH3 51.8 293 Carbon dioxide CO2 0.145 298 Hydrogen chloride HCl 82.3 273 Nitrogen N2 0.0019 293 Oxygen O2 0.0043 293 Solids Formula Solubility g/100-mL Temperature /K Aspirin HC9H7O4 0.33 298 Baking soda NaHCO3 10 298 Caustic soda NaOH 42 273 Marble CaCO3

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

    57 kJ = 5700 J Temperature change = Q / (m x c) = 5700 / (50 x 4.2) = 27.143 �C 5. For the reaction of 25 cm3 of 5 M HCl and 5 M NaOH Moles of NaOH = c x v = 5 M x 0.025 dm3

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

    time so that the same concentration and amounts will be obtained each experiment. I will also be controlling the chain length of the acid and alcohol I use in the reaction. If I change the chain length of the reactants different products are going to be produced and may affect the equilibrium constant of the reaction.

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