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

The aim of this investigation is to determine the relative atomic mass of Lithium by two different methods:

Extracts from this document...

Introduction

The aim of this investigation is to determine the relative atomic mass of Lithium by two different methods: * By measuring the volume of Hydrogen produced when Lithium is dissolved in water; * And by titrating the Lithium Hydroxide produced. As a basic safety measure, goggles should be worn during the entire experiment and titration. It is important not to handle the Lithium with your bare hands. Lithium reacts violently with water, which may be present on your hands. When Lithium reacts with water it forms Lithium Hydroxide (LiOH) solution, which is corrosive - this means it can cause burns. You should transport the Lithium using tongs or by placing it inside a dry container. It is important not to spill the Hydrochloric Acid when handling it as it also corrosive and can cause burns. ...read more.

Middle

calculate the number of HCL used in the titration. ii) Deduce the number of moles of LiOH used in the titration. iii) Calculate the number of moles of LiOH present in 100cm� of the solution from the first reaction. iv) Use this result and the original mass of Lithium to calculate the relative atomic mass of Lithium. i) 0.1 moles of HCL in 1000ml 0.0001 moles of HCL in 1ml 0.003225 moles of HCL in 32.25ml ? 0.003225 moles of HCL used ii) This means I used 0.003225 moles of Lithium. iii) 0.003225 x 4 (as 25cm� was used) = 0.0129 iv) Relative Atomic Mass of Lithium: Mr = mass � moles = 0.10 � 0.0129 = 7.75 Evaluation The dissolving of the Lithium in distilled water was more accurate than the titration. But together the two reactions were quite accurate, gaining relative atomic masses of 7.50 and 7.75. ...read more.

Conclusion

Like oil, the area around the Lithium, which had reacted with air, is making the weighing and experiment inaccurate. The only way to overcome this problem is to prepare the Lithium and do the experiment in a vacuum. You could also carry out the preparation in a controlled inert environment. * When you are placing the bung in the conical flask. In order to add the Lithium to the water, you have to remove the bung, and replace it as quickly as possible when the Lithium is in the flask. This method allows some Hydrogen to escape if the bung is not immediately replaced. This error can be highly influential over the final accuracy of the experiment. The only way to overcome this problem is to develop a system that allows you to place the Lithium in the water without letting any of the Hydrogen escape. Possibly, a way of placing the Lithium in the conical flask without it touching the water, and then by knocking the flask you release the Lithium into the water. ...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. How much Iron (II) in 100 grams of Spinach Oleracea?

    0.0001897 mol dm-3 x 5 = 0.000316166 mol dm-3 3 Now that I know the mols of Iron (II) present in 10 cm3 of spinach extract solution I can use this to work out the moles of Iron (II) present in 100 cm3 of spinach extract solution.

  2. to determine the relative atomic mass of lithium. We will be doing this via ...

    Number of moles The mass of lithium used is 0.099g so to find the relative atomic mass of lithium: Relative atomic mass = 0.099 = 6.6742 0.014833 So the Relative Atomic Mass of Lithium is 6.67 (to 3 significant figures).

  1. Determine the relative atomic mass of lithium.

    + HCl(aq) LiCl(aq) + H2O(l) Method 1 : Apparatus 1 x Measuring cylinder (250cm�) 1 x Conical flask (250cm�) 1 x Rubber bung 1 x Tube 1 x Container 1 x Electronic scale 1 x Distilled water 1 x Lithium 1 x Goggles 1 x Gloves 1 x Lab coat The apparatus should be set up like this - Method 1.

  2. Determination of the relative atomic mass of Lithium.

    + HCL (aq) LiCl (aq) + H2O (l) Mole ratio LiOH : HCL 1 : 1 = 0.0129mol : 0.0129mol Since I used 10cm� of LiOH of the original 100cm�: 0.0129mol = 1.29 x 10-3mol 10 Step 4 : Volume of HCL (cm�)

  1. To find the relative atomic mass of a sample of Lithium.

    Bubbles in the end of the burette could account for any inaccuracies and during the second titration I thought I had reached the end point but when I swirled the solution more and washed the flask sides with distilled water I found the solution turned purple again.

  2. Determination of the relative atomic mass of lithium.

    The equation for this is concentration of lithium (0.10g) multiplied by volume of hydrochloric acid divided by 1000. Number of moles of HCl = concentration x volume/1000 0.10 x 39.27/1000 = 0.0393 The answer to this calculation is 0.00393 The ratio of this experiment is going to be: Ratio HCl

  1. Determination of the relative atomic mass of lithium.

    So I removed the stopper and added the lithium before reuniting the two back together, I did this as quickly as I could. After about 1 minute the reaction had stopped and all the gas had been collected and I read it off as being 95cm3, but to record the actual volume of gas collected, I subtracted the two.

  2. Determination of the relative atomic mass of Lithium

    * As hydrogen was in a ratio of 1 : 2, I had to multiply the number of mols (0.00775) by 2 to get an answer of 0.0155 mols. * And lastly, to find the relative atomic mass of Lithium, I had to substitute the mass (0.11g)

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