1Mohamed Karous

Aim of Investigation:

I am going to be investigating the energy transferred by neutralisation. I am going to investigate this by conducting a range of experiments, to research what is the best variable that I can use to measure the amount of energy transferred.

Scientific Research

Different Equations need to know:

Acid + Alkali Salt + Water

Different acids available are the following:

Hydrochloric Acid

Nitric Acid

Sulphuric Acid

Those three acids are the three possible acids that I can us for my real experiment I am going to see which is the best acid to us in my preliminary as that is when im going to test which acid does the best reaction also I am going to see which concentration is the best for the reaction.

Each acid gives a specific salt when it is neutralised here is a list:

Hydrochloric Acid = Chloride

Nitric Acid = Nitrate

Sulphuric Acid = Sulphate

All acids realise hydrogen ions when they dissolve and all alkali realise hydroxide ion. In a neutralisation reaction the hydrogen ions react with hydroxide ions forming water. In any chemical reaction the bonds between the chemical must be broken to rearrange the atoms into products. This energy is called activation energy.

There are two types of reactions:

Exothermic Reactions

What is an Exothermic Reaction?

These are reactions that transfer energy to the surroundings. The energy is usually transferred as heat energy, causing the reaction mixture and its surroundings to become hotter. The temperature increase can be detected using a thermometer. Some examples of exothermic reactions are:

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1) Burning

2) Neutralisation reactions between acids and alkalis

3) The reaction between water and calcium oxide

Endothermic Reaction

What is an Endothermic Reactions?

These are reactions that take in energy from the surroundings. The energy is usually transferred as heat energy, causing the reaction mixture and its surroundings to get colder. The temperature decrease can also be detected using a thermometer. Some examples of endothermic reactions are:

Electrolysis

The reaction between ethnic acid and sodium carbonate

The thermal decomposition of calcium carbonate in a blast furnace

In Conclusion Exothermic reactions transfer energy to the surroundings. Endothermic reactions take in energy from the surroundings. Reversible reactions are where the products can react to remake the original reactants. If the forward reaction is exothermic, the reverse reaction is endothermic.

The following is a diagram of an endothermic and exothermic Reaction which is a graph.

Chemical reaction often involves changes in energy when an acid and an alkali react together the energy change is called the heat of neutralisation. You can calculate the energy change of the reaction using the formula:

Energy Change (J) = M x S x T

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You are going to mix different the volumes of acid and alkali solutions and measure the change in temperature which takes place

M = mixture S = the captivity T = tempter

Ionic Equations

A chemical equation is symbolic representation of a chemical reaction where the reactant entities are given on the left hand side and the product entities on the right hand side. Here is an example:

Iron + copper (II) sulphate iron sulphate + copper.

Fe(s) + CuSO4 (aq) FeSO4 (aq) + Cu(s)

By writing the Ionic Equation would show what state it is in.

Collision Theory

Some reactions are slow, such as rusting, and some are fast, like burning. The rate of reaction depends on the temperature and concentration of the reactants, and the surface area of any solid reactants. The rate of reaction can be found by measuring the amount of reactant used up, or the amount of product formed, in a given time. Catalysts increase the rate of a reaction without being changed themselves by the end of the reaction.

Different example, rusting is a slow reaction: it has a low rate of reaction. Burning and explosions are very fast reactions: they have a high rate of reaction.

Here is a diagram of the collision theory:

Reactions can happen at different rates. Reactions that occur slowly have a low rate of reaction. Reactions that happen quickly have a high rate of reaction.

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Different Factors

In order to get the best factor – I am going to have to investigate each factor that is possible.

Changing the Volume

Firstly the first factor that I could investigate is that how the energy transfers changes as the volume increases. The experiment that was going to take place was going to be an Exothermic Reaction – an exothermic reaction is when energy is emitted the energy in this experiment is released via heat. So in the equation in working out the energy transferred you can see the volume is heavily relied in the end of the equations result. So at 30 ml of potassium hydroxide with 20 ml of hydrochloric acid will have an energy transferred of about 2100j – but with 20ml of potassium hydroxide there will be 2300j – the reason why this happens is because they are now at its peak – that is the maximum amount of energy transferred for that volume but as you increase the volume or decrease it the energy transferred will decrease as it will become disproportionate – but the closer the 20ml of hydrochloric acid the energy transferred increases 500j every time. When it passes 20ml of potassium hydroxide.

Changing the Acid

The Effect of Heat on Neutralisation When the Acids Are Varied .I shall carry out several experiments investigating the heat of neutralisation when the acids and alkalis used are differentiated to see the different effects this has on the heat of neutralisation. Theory:

H+ + OH- =H2O

In my experiments I have decided to use the following acids and

To investigate the effect different combinations that these acids and alkalis have I will use the following combinations: Strong acid with a strong alkali (preliminary experiment) - HCl and NaOH Strong acid with a strong alkali - HCl and KOH, Strong alkali with a weak acid - NaOH and CH3OOH strong monobasic acid with a strong dibasic alkali - HNO3 and NaOH Strong dibasic acid with a strong monobasic alkali - H2SO4 and NaOH .Strong acid with a weak alkali - HCl and NH3. The main element that I need to consider if I pick this is that is it going to provide me enough comparable data that is relevant for me and enough for me to investigate.

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Preliminary Experiment

In the preliminary I need to find out what are the best acid and alkali to use and which acid and alkali gives me the best energy transferred. Also I need to find which the best insulator is after I choose an acid because to make my results the most reliable I need to find which variable will be the best to use. The Possible experiment that I could conduct is to measure the amount of energy transferred using the process of neutralisation. We could vary the volume of acid or alkali. This would vary the amount of energy transferred as in the formula working out the amount of energy transferred the volume of the experiment has a big impact in the amount of energy transferred but it won’t be more when the alkali and acid are at the exact same volume as that would be in the ideal ratio to acid and alkali to react with each other. But the results would be affected due to the equipment that we are going to us so we would make sure we can insulate the cups so the temperature doesn’t drop so we need to get the best insulator so the energy transferred doesn’t get affected so in the preliminary experiment I am going to find the best insulator so our results are more reliable.

Preliminary Hypothesis:

I believe that the best insulator in the reaction is going to be cotton not bubble wrap as in clothing they use cotton to insulate and it does the best jobs and they don’t make it out of bubble wrap as plastic conducts heats quite fast unlike cotton as cotton heats up slowly so not much energy is wasted which will make the experiment more reliable and I think that hydrochloric acid and sodium hydroxide as they are the most concentrated acids and alkali which would therefore give us the best results to interpret. I think if we use the strongest alkali and acids available we could get the highest amount of energy transferred to do this thee would be a bigger difference in each result this would let us identify a correlation within the results. Also by using the strongest alkali and acid available reduces the risk in getting results that have no correlation. I’m going to have to try every combination of alkali and acid to get the best combination, with the best and most reliable results in the preliminary. The reason why I think that the temperature is going to increase is because the reaction that I’m going to take past is an Exothermic Reaction. An exothermic reaction is when energy is emitted the energy in this experiment is released via heat. So in the equation in working out the energy transferred you can see the volume is heavily relieved in the end of the equations result. So at 30 ml of potassium hydroxide with 20 ml of hydrochloric acid will have an energy transferred of about 2100j – but with 20ml of potassium hydroxide there will be 2300j – the reason why this happens is because they are now at its peak – that is the maximum amount of energy transferred for that volume but as you increase the volume or decrease it the energy transferred will decrease as it will become disproportionate – but the closer the 20ml of hydrochloric acid the energy transferred increases 500j every time. Furthermore, with the different materials I’m going to test which one is more of a better insulator so I predict that the wool will be a better insulating only allowing 1 degree Celsius but the bubble wrap will allow 2 or 3 degrees escape. The reason why up think this will happen is because wool is denser which will then insulate the heat is trying to escape.

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Equipment Why?Water I need water to neutralise the acids and alkalises which I need to

put another chemical in it I will just use tap water also I will do a few dilutions I am going to us cold tap water as it reduces any risk in burning as with hot water there is a high risk in people being burnt by water

Pipette I will be using a pipette to get the most accurate volume of acid or alkali but to make it more reliable I could use a digital pipette but we don’t have this available in school so we are going to use the one available which is the standard pipette

Ph scale I need a Ph. scale to see if the acid or Alkali has neutralised and overall see which acid or alkali is stronger and to get the exact Ph. As it gives us a colour it isn’t really reliable because different people perceive colours in different ways and colour changes in the lighting circumstance.

Universal Indicator I am going to use a universal indicator to indicate the ph. of the substance. By as the Ph. scale it gives us a colour it isn’t really reliable because different people perceive colours in different ways and colour changes in the lighting circumstance.

Measuring Cylinder I am going to use a measuring cylinder to get accurate volumes of acids or alkalise but to make in more accurate I could get newer measuring cylinders as the measuring cylinder in quite hard to read.

Beaker I am going to use a beaker to place the acid to see which acid or alkali is the best for the experiment a big limitation is that it losses a lot of heat but I need to find which is the best alkali or acid

Polystyrene Cup I am going to be using a Polystyrene cup as it is quite a good insulator and I want to see which the best insulator is and I need it to compare it to cotton wool.

Cotton wool I am going to use cotton to see which the best insulator is and in theory it should be a good insulator, but I need to make sure each element has the same amount of thickness to make sure it’s a fair test.

Bubble Wrap I am going to use bubble Wrap to see which the best insulator is and in theory it should be a good insulator but I need to make sure each element has the same amount of thickness to make sure it’s a fair test.

Elastic Bands I am going to be using an elastic band to hold the insulators on the cup.

Sodium Hydroxide It’s a chemical that we are going to test to see which chemical is the best

Hydrochloric Acid It’s a chemical that we are going to test to see which chemical is the best

Potassium Hydroxide It’s a chemical that we are going to test to see which chemical is the best

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Ammonium Hydroxide It’s a chemical that we are going to test to see which chemical is the best

Thermometer We need a thermometer to see the temperature to then calculate how much energy was transferred if we used a digital thermometer which gives temperature to 2 dp would be more reliable.

Digital Stop Watch We have a digital stop watch because it’s more reliable as it records to two decimal places. Unlike using the clock as if we use the clock it would give us less reliable results than what a stop watch would give me

Safety Glasses We use a safety glasses to protect our eyes from any acid to touch our eyes and blind us

Diagrams:

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Method:

1) Collect all equipment stated above2) Set the Experiment in the diagram3) Measure 20 ml of each acid and Alkali and use the pipette and the measuring

cylinder4) Measure the temperature of the acid and alkali5) Do the following Combinations: Sodium Hydroxide and Hydrochloric Acid. Potassium

Hydrochloric Acid. Hydrochloric Acid Amnion Hydroxide6) Measure the temperature with a thermometer of each of the combination7) Put the acid and alkali in the beaker and measure the temperature with the

thermometer8) Write it down.9) Choose the Acid and Alkali that gives you the best result10) Do the same thing in step 311) Measure the temperature of the acid and alkali12) Place the two acids in the Polystyrene cup with bubble wrap 13) Repeat step 9 and 1014) Put the acid and alkali in the polystyrene cup with cotton wool.15) Records Results and conclude which Insulator is the best.

Risk Assessment:

1) Biological Hazard: Safety goggles must be worn at all times while in the laboratory. This rule must be followed whether you are actually working on an experiment or simply writing in your lab notebook. You must wear safety goggles provided by the chemistry department.

2) Biological Hazard: Contact lenses are not allowed. Even when worn under safety goggles, various fumes may accumulate under the lens and cause serious injuries or blindness.

3) Biological Hazard: Long hair must be tied back when using open flames.

4) Biological Hazard: If hot water touches you rinse immediately with cold water

5) Biological Hazard: If any glass is shattered keep away don’t touch it and wait for a teacher to sweep it up.

6) Physical Hazard: Don’t run around

7) Chemical Hazard: If you come into contact with acid and alkali rinse with clean water immediately

8) Chemical Hazard: Do not consume the acid or alkali

9) Chemical Hazard: Fouling: - This is caused by deposits of scale, dirt, sand and / or other solid deposits on the conducting surfaces. Coke formation in furnace tubes and other causes

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of semi-blockage of tubes will drastically decrease efficiency in an exchanger. Such problems will result in shutdown for cleaning and possible tube replacements. Many of these problems can be avoided by proper operation and fluid treatment - filtration, corrosion inhibition, furnace firing control Etc.

10) Chemical Hazard: Air pockets: - The formation of air pockets in exchanges due to improper venting at start up, or build of gas from light materials, will affect the heat transfer rate. This can be avoided by venting all air or gas out at start up and periodically venting gases as required.

11) Physical hazard: Leakage: -Most leakages occur due to gasket failure - replacement of gaskets will be necessary. Internal leakage due to tube failure will cause contamination of the lower pressure fluid by the ingress of higher pressure fluid. This will require tube 'plugging' or replacement. Tube failure generally occurs due to corrosion, excessive pressure or by failure of the welded or rolled fitting of the tubes into the tube-sheets.

Results:

Acid Alkali Temperature Before°C

Temperature After°C

Hydrochloric Acid Sodium Hydroxide 19 27Hydrochloric Acid Potassium

Hydroxide21 31

Hydrochloric Acid Amnion Hydroxide 23 29

Through the results of the preliminary I have therefore concluded the best alkali to use is potassium Hydroxide as this gave me the best results which therefore say that it was the stronger alkali now I am going to choose the best insulator.

Insulator Temperature Before°C

Temperature After°C

Cotton Wool 23 34Bubble Wrap 24 31

In the results I therefore conclude that cotton is a better insulator as it insulates the temperature the best as it loses lees energy as you can see in results so in conclusion for the actual experiment I will use Potassium hydroxide and Hydrochloric Acid finally the insulator is going to be cotton wool.

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Final Experiment

For the main experiment I want to find out how the volume of the alkali affects the amount of energy transferred and the temperature given off.

Main Hypothesis

I believe that as the volume of the alkali decreases the amount of energy transferred reduces as the reaction of the experiment will decrease as there will be less volume to react with as in the equation of calculation the amount of energy transferred relies in the volume and in theory as the volume decreases so does the energy transferred. This would vary the amount of energy transferred as in the formula working out the amount of energy transferred the volume of the experiment has a big impact in the amount of energy transferred but it won’t be more when the alkali and acid are at the exact same volume as that would be in the ideal ratio to acid and alkali to react with each other. But the results would be affected due to the equipment that we are going to us so we would make sure we can insulate the cups so the temperature doesn’t drop so we need to get the best insulator so the energy transferred doesn’t get affected so in the preliminary experiment I am going to find the best insulator so our results are more reliable. As I stated in the Preliminary experiment that the experiment that was going to take place was going to be an Exothermic Reaction – an exothermic reaction is when energy is Emitted the energy in this experiment is released via heat . So in the equation in working out the energy transferred you can see the volume is heavily relied in the end of the equations result. So at 30 ml of potassium hydroxide with 20 ml of hydrochloric acid will have an energy transferred of about 2100j – but with 20ml of potassium hydroxide there will be 2300j – the reason why this happens is because they are now at its peak – that is the maximum amount of energy transferred for that volume but as you increase the volume or decrease it the energy transferred will decrease as it will become disproportionate – but the closer the 20ml of hydrochloric acid the energy transferred increases 500j every time. When it passes 20ml of potassium hydroxide.

Equipment Why?Pipette I will be using a pipette to get the most accurate volume of acid or

alkali but to make it more reliable I could use a digital pipette but we don’t have this available in school so we are going to use the one available which is the standard pipette

Ph. scale I need a Ph. scale to see if the acid or Alkali has neutralised and overall see which acid or alkali is stronger and to get the exact Ph. As it gives us a colour it isn’t really reliable because different people perceive colours in different ways and colour changes in the lighting circumstance.

Universal Indicator I am going to use a universal indicator to indicate the ph. of the substance. By as the Ph. scale it gives us a colour it isn’t really reliable because different people perceive colours in different ways

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and colour changes in the lighting circumstance.Measuring Cylinder I am going to use a measuring cylinder to get accurate volumes of

acids or alkalise but to make in more accurate I could get newer measuring cylinders as the measuring cylinder in quite hard to read.

polystyrene Cup I am going to be using a polystyrene cup as it is quite a good insulator and I want to see which is the best insulator and I need it to compare, but after comparing this

Cotton wool I am going to use cotton to see which is the best insulator and in theory it should be a good insulator

Elastic Bands I am going to be using an elastic band to hold the insulators on the cup.

Hydrochloric Acid That is the acid I chose as it got me the best results in the preliminary

Potassium Hydroxide That is the alkali I chose as it got me the best results in the preliminary

Thermometer We need a thermometer to see the temperature to then calculate how much energy was transferred if we used a digital thermometer which gives temperature to 2 dp would be more reliable

Digital Stop Watch We have a digital stop watch because it’s more reliable as it records to two decimal places.

Diagram:

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Method:

1) Collect all the equipment stated in the equipment table2) Setup the experiment as shown in the diagram3) Conduct the following Acid to Alkali Ration:

Hydrochloric Acid Potassium Hydroxide20 ml 30 ml20 ml 25 ml20 ml 20 ml20 ml 15 ml20 ml 10 ml20 ml 5 ml

4) For each ratio you use the pipette to measure the acid and the alkali5) After measuring you squeeze the acid or the alkali into each test tube.6) To do the dilutions the dilutions you measure the amount of acid or alkali stated 7) above8) Put the dilutions in measuring cylinder9) Put the cotton around the polystyrene cup and attach with elastic band10) Put the thermometer in the measuring cylinder11) Measure the temperature of the acid and alkali12) Put both chemicals in the cup and stir and after a minute measure the temperature

with the thermometer13) do step 5 6 7 for all ratios listed above14) Repeat the experiment 3 times

The reason I chose this method was because it was easy step by step instructions to commit a successful experiment. We used 20 ml as it would get us the best results as they would add to 40 ml and it would give us the best results. We repeated the experiment 3 times to make sure no human errors affect the overall result.

Fair Test

The independent variable I plan to change in this investigation is the volume of potassium hydroxide.

The Variable is going to discrete as I using a thermometer, not a digital thermometer.

The Dependent variable I plan to measure is the volume of hydrochloric acid

The variable I will be controlling to keep the test fair is the measuring cylinder, thermometers starting and the volume of hydrochloric acid.

Rinsing off the measuring cylinder to neutralise the acid and alkali

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After using the thermometer wash the thermometer so you can sustain the original temperature.

To keep it a fair test we are going to put the thermometer at the same place which is shaded so the temperature doesn’t get affected which would affect the result to the energy transferred.

Risk Assessment:

Biological Hazard: Safety goggles must be worn at all times while in the laboratory. This rule must be followed whether you are actually working on an experiment or simply writing in your lab notebook. You must wear safety goggles provided by the chemistry department.

Biological Hazard: Contact lenses are not allowed. Even when worn under safety goggles, various fumes may accumulate under the lens and cause serious injuries or blindness.

Biological Hazard: Long hair must be tied back when using open flames.

Biological Hazard: If hot water touches you rinse immediately with cold water

Biological Hazard: If any glass is shattered keep away don’t touch it and wait for a teacher to sweep it up.

Physical Hazard: Don’t run around

Chemical Hazard: If you come into contact with acid and alkali rinse with clean water immediately

Chemical Hazard: Do not consume the acid or alkali

Chemical Hazard: Fouling: - This is caused by deposits of scale, dirt, sand and / or other solid deposits on the conducting surfaces. Coke formation in furnace tubes and other causes of semi-blockage of tubes will drastically decrease efficiency in an exchanger. Such problems will result in shutdown for cleaning and possible tube replacements. Many of these problems can be avoided by proper operation and fluid treatment - filtration, corrosion inhibition, furnace firing control Etc.

Chemical Hazard: Air pockets: - The formation of air pockets in exchanges due to improper venting at start up, or build of gas from light materials, will affect the heat transfer rate. This can be avoided by venting all air or gas out at start up and periodically venting gases as required.

Physical hazard: Leakage: -Most leakages occur due to gasket failure - replacement of gaskets will be necessary. Internal leakage due to tube failure will cause contamination

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of the lower pressure fluid by the ingress of higher pressure fluid. This will require tube 'plugging' or replacement. Tube failure generally occurs due to corrosion, excessive pressure or by failure of the welded or rolled fitting of the tubes into the tube-sheets.

Reliability and accuracy

Reliability and accuracy are critical parts in the coursework they will allow me to get Reliable as well as accurate results.

In order to make my test as reliable as I can I will have to repeat the tests three times or more. I have specifically chosen 3 because in my preliminary I only tested once and it wasn’t enough it was very unreliable.

To keep my test fair I will always do the experiment in the same place as doing it in a shaded and sunny side to avoid any temperature change

In my preliminary I found that labelling bottles were very useful and it helped me not pour acid in to a measuring cylinder that was used previously with an alkali

Analysis of Results:

After reviewing our results I conclude that there is a positive correlation when it comes to volume of acid to energy transferred but at 30ml it goes the other way as after 25ml the energy transferred goes down as the volume from acid to alkali is at the opposite rate. But the results do support my hypothesis but I will discuss this further later.

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Secondary Results by Robin Jones

Analysis of Results and Secondary results:

After reviewing the results I realised that they both have the same correlation which could suggest that the results are reliable. But the results aren’t exactly the same which could suggest the case of human error. If we repeat the experiment we need to find a way to reduce the probability of human error as that is the main reason why results become unreliable.