To work out the concentration of a substance from the heat energy of neutralisation.

hold acid and alkali when reacting) 2-heat proof mat 6-Buret 3-tongs 7.goggles(to protect eyes) 4-glass beakers Variables: There are many variables in this experiment that can affect it. 1.amount of acid/alkali 2.concentration of acid/alkali 3.the apparatus that are used eg beakers 4.The temperature of the room 4.The cleanness of the apparatus e.g. alkali is still left in the polystyrene cups it will affect the rate of acid reacting with the original amount of alkali simply because the is more of it. 5.awearness e.g. if you are messing around then you may not take notice of the max. temp of the substances reacting Procedure: We are going to use a lot of dangerous chemicals during this experiment so the first thing I will do is to make sure all safety recommendations are met and are taken seriously.The next thing to do is get the acid and alkali from the sides of the room where they are allocated.Once that is done we have to measure the amount of acid and alkali that we want to react using a buret,It is important that we look at the measurement at eye level as if that is not done then you will get the wrong measurement and the experiment will be void will be doing this experiment three times so as to ... get a average and to make sure the results are accurate.It is important that I always use the same volume in each test and only changing the concentration of the water,otherwise the results will be totally different each time and making the experiment an unfair test as I am changing the variables The oxford international CD-ROM states-neutralization (in chemistry), the reaction between an acid and a base or alkali, in which a salt and water are formed. The resulting solution is neutral--that is, neither acidic nor alkaline. The positive hydrogen ions of the acid are neutralized by the negative ions from the base. A neutral solution has a pH of 7,This means that the result we get from our experiment should be of PH7 and should not be acid or alkali,If the result we get behind is of a higher or lower PH7 then obviously the heat gain will not be highest and there is more alkali than acid and vice versa. Obtaining- After the experiment finished I finally managed to get a table and a graph completed- Volume of acid Volume of alkali temperature (C) Average 1. 2. 3. 0 50 5 45 21c 22c 21c 21c 10 40 25 25 25 25 15 35 27 26 26 26 20 30 29 29 29 29 25 25 31 31 31 31 30 20 29 29 29 29 35 15 27 27 26 27 40 10 24 23 24 24 45 5 19 19 19 19 50 0 During this experiment I used- 1.Beret 2.beakers 3.Polysyreine cups 4.Thermometer I have used the buret and thermometer for accuracy,It is important that I get the most accurate result from the test to make...the test as fair as possible.i used the best equipment that would give me the most accurate result during this experiment Analysing results- As we can see from the table it is plain to see that the highest heat rise was the test with equal amounts of alkali and acid(25cm-25cm).I have done a graph to show this with a line of best fit.The reason that we get the highest heat rise from the same amounts of acid and alkali is that as the acid and alkali that I used has a concentration of 2 molar then when we have an equal amount of acid and alkali then there is a 2:2 molar ratio thus meaning that every mole is reacting with each other.If we had for example a concentration of 30 cm alkali and 20 cm acid then there would not be a equal ratio of acid and alkali moles meaning that there would be in theory 10 cm of alkali moles left.as we can all see from the table it does not really matter if there is a 20 cm of acid and 30 cm of alkali because both the reaction gives roughly the same temperature as a 30 cm of alkali and 30 cm of acid reaction.this also goes for the rest of the table.My prediction has been proved correct as I said that the reaction with equal amounts of alkali and acid would have the best and greatest heat rise.i shall now use my equation to work out the concentration of both 25 cm and 50 cm. C (NaOH) = n x 1000 V = 2 x 1000 25.4 =0.004 dm-3 Evaluating As we can see from my graph the experiment was quite succesful,no freak results and it worked like I predicted it would.There were no anomalous results and all results were very accurate I think I chose the best method for working out the concentration otherwise there could be some freak results etc.Allthough my method was not very safe as it meant keeping a lot of alkali and acids lying around at the workbench which could lead to an accident.But I believe chose the method that would give me the most accurate results.I believe I could have improved my results in many ways,The first being that many times during the experiment I was distracted by other people and not watching my work so I think I could have improved my results by taking more care.The second being safety,I spilled my acid on three occasions which could have been deadly luckily I cleaned it up and no one got hurt.I could have also cleaned up better and cleaned my apparatus up better this would have lead to better results.I believe doing this could have helped a lot in this experiment.Overall I thikn the experiment was a success an I think in some ways I could of done better but in other ways I performed to the best of my ability.