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

Determination of the relative atomic mass of Lithium.

Extracts from this document...


Chemistry Coursework Stephanie Knowles Determination of the Relative Atomic Mass of Lithium Analysing: We followed the plan set to us and, for method one, attempted capturing the hydrogen gas produced by the reaction of lithium and water. We decided to do this four times to gain more reliable results, and to identify any anomalies. On our first attempt we used 0.10g of lithium, this amount produced 90cm� of hydrogen gas, on our second attempt we used 0.9g of lithium, which produced 130cm� of hydrogen. At this point it was clear that there was a mistake as bigger quantities of lithium would have reacted more, producing more gas, or at least the amount should have been around the same as our first attempt. On the third try we used 0.13g of lithium- this reaction caused 230cm� of gas to be collected. Making the conclusion that one of our 0.9g or 0.10g of lithium results was incorrect, we attempted a 0.10g of lithium again this produced 250cm� of gas, again not agreeing with our result for the 0.13g of lithium. ...read more.


We need to know how many grams produces 1 mole, therefore divide 1 mole by 0.020mols: 1mol - 0.020mols = 5g Giving the answer that the relative atomic mass of lithium, is 5. Procedure Two- Calculate the number of moles of HCl used in the titration- We can do so using this balanced equation: LiOH (aq) + HCl (aq) LiCl (aq) + H O (l) 12.6 cm� (average titration amount) The HCl has a concentration of 0.1mol dm�. We must use this formula- 12.6 1000 x 0.1 = 0.00126 Therefore 0.00126mols HCl were used. Deduce the number of moles of LiOH used- From the above equation we can see that the same amount of HCl is used as LiOH so there is also 0.00126mols of LiOH used. Calculate number mols LiOH present in 100cm �of the solution from procedure one- We know that there was 0.00126mols present of LiOH in 25cm�, to calculate how much was present in 100cm�, multiply by 4: 4 x 0.00126mols = 0.005mols Calculate the relative atomic mass of lithium- The relative atomic mass is the same as 1mole of lithium. ...read more.


Other then human error the only explanation for this huge difference was the lithium we used. Lithium must be stored in oil as after a minute or so in the presence of moisture and oxygen the surface becomes tarnished to a grey colour and perhaps the occurrence of lithium oxide as well. This might well have affected the collected lithium hydroxide in the conical flask therefore affecting the titration. Slicing an entirely silvery coloured fresh piece of lithium and using it instead of a piece from the outside of the lithium 'block' could have prevented this. In conclusion, the experiment was not a successful one- the apparatus problems and the lithium used (which would have also explained the diverse amounts of hydrogen collected in procedure one) would explain the very different results of the relative atomic masses from each other and the correct one. With the adjustments suggested mad the results would have been more reliable and closer to the truth. ...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 Classifying Materials 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 Classifying Materials essays

  1. The rates of reaction between CaCO3 and HCL

    From both samples east and west the curve of best fit is this shape which shows that reaction followed the norm but for each there are two anomalous results. For East * (120 , 0.30) * (165 , 0.32) For West * (135 , 0.36)

  2. Free essay

    Periodic table

    are inserted into the chain We don't know what characteristics a baby will have its all random - in the same way getting a genetic disorder is also random. Eugenics is trying to improve the characteristics of human populations by selective breeding or genetic engineering.

  1. Affect of concentration on reaction

    an electronic weigh that can measure up to 3 decimal places, measure acid more accurately by using a burette and also when I was doing the preliminary experiments I notice the reactions often splashed out some acid, that could make the results inaccurate because mass is loss when acid is

  2. The role of mass customization and postponement in global logistics

    extend the definition to the five MC Performance Dimensions, namely: Design and new product development, Supplier management and supply chain agility, Production flexibility and capacity management, Variety and inventory management, Communications and information management Design and new product development Satisfy customer interests by efficiently (time and resources/cost)

  1. The relative atomic mass of lithium

    The solution turned pink - The next thing to do was to put to put the HCl into a burette, measure the initial volume then relies the HCl into the conical flask slowly until the solution turns colourless, the final volume is then recorded.

  2. Determination of the relative atomic mass of Lithium.

    Results - LiOH (aq) + HCl (aq) LiCl (aq) + H O (l) � Titre Initial volume of acid (ml) Final volume of acid (ml) Volume of acid used (ml) 1 0 42.2 42.2 2 0 42.7 42.7 3 0 42.1 42.1 4 0 31.8 31.8 Average result of titration is 42.3 ml.

  1. Determination of the relative atomic mass of lithium

    When cutting the lithium you must make sure you cut the appropriate size you require and make sure that the lithium is oil free. Also when using the phenolphalein and shaking the mixture you must make sure that how you add the phenolphalein and the way you shake the funnel

  2. Gravimetric Determination of Phosphorus in Plant Food

    Finally, pour two 10 mL portions of 75% isopropyl alcohol through the filter paper. Once properly filtrated, remove the filter paper, place it on a numbered watch glass[3]. Repeat the above procedure with two more samples. Once the three samples of MgNH4PO4?6H2O is thoroughly dry, weigh the filter papers containing MgNH4PO4?6H2O.

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