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

MASS OF LITHIUM

Extracts from this document...

Introduction

DETERMINING THE MASS OF LITHIUM METHOD 1 RESULTS Mass of lithium used 0.12g Amount of hydrogen gas produced 182cm� TREATMENT OR RESULTS 2Li(s) + 2H2O(l) --> 2LiOH(aq) + H2(g) Moles of hydrogen gas collected Moles of H2 volume / 24000(cm�) 82 / 24000 0.007583333 moles Moles of H2 0.0076 moles Lithium that reacted H2 : Li 1 : 2 0.0076 : 2 � 0.0076 0.0076 : 0.0152 Moles of Li 0.0152 moles Relative atomic mass of lithium R.A.M mass / moles 0.12 / 0.0152 7.894736842 R.A.M of Li 7.8947 METHOD 2 RESULTS Titration of aqueous LiOH with 0.100 mol dm-3 HCl. Start (cm�) End (cm�) Titre (cm�) 0 34.90 34.90 0 34.80 34.80 0 34.90 34.90 Average result (34.80 + 34.90) / 2 = 69.7 / 2 = 34.85 TREATMENT OF RESULTS LiOH(aq) + HCl(aq) --> LiCl(aq) + H2O(l) Moles of HCl used in titration Moles of HCl concentration � (volume / 1000) 0.100 � (34.85 / 1000) 0.003485 moles Moles of HCl 0.0035 moles LiOH used in titration HCl : LiOH 1 : 1 0.0035 : 0.0035 Moles of LiOH 0.0035 moles Number of moles of LiOH present in 100cm� of solution from method 1 25cm� of LiOH is pipette each time. ...read more.

Middle

Also the oil lithium was dipped in was hard to remove completely. This could have also affected my result. It was also hard to put the stopper quickly on the conical flask, and this could have lead to some of the gas escaping, making the hydrogen gas produced to be less, affecting the end result. Although, this could not have caused a great inaccuracy in the result because it's due to human error. In both methods, there may have been errors in the cleanliness of the equipment as reagents from other experiment may have been present in the glassware, which can cause potential errors in the experiment. In method 2, taking the readings at eye level from the burette was not that accurate and the reading may have been in or out by 0.1 ERRORS IN MEASUREMENT When measuring out for the experiment, inaccuracy in measurement may have affected my final result. In method 2, when using the phenolphthalein, it's difficult to precisely use the same amount of drops when adding it to the LiOH. Lithium was measured using a 2decimal place scale. The measurement may have been precise, but since an oxide layer may have formed on the lithium, there may be some oxygen measured with the lithium, meaning that it's not the accurate mass of lithium used, thereby affecting the final result. ...read more.

Conclusion

and increase the volume of water, which will increase the amount of LiOH produced; therefore I will be able to do the titration more, and get more results which I can then compare and use the best one to get the best result for the experiment. Also, greater mass of lithium means there will be a smaller margin of error when measuring it out. I could have used a larger gas syringe perhaps a 200cm�. This will change the error margin from �1cm� to �0.5cm�, thereby increasing the accuracy of the experiment. I will also make sure that I use lithium from an inert atmosphere to prevent oxide layer forming, this will ensure that I'm only taking the mass of the lithium, and not the mass of lithium and the oxide layer. This will make my result more accurate. CONCLUSION From the evidence I have collected during this experiment, I have come to the conclusion that method 1 of finding the relative atomic mass of lithium is more reliable in comparison to method 2. This is because method 1 has the relative atomic mass which is close to the R.A.M of lithium, and more errors occur in method 2 than method 1. ?? ?? ?? ?? ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our AS and A Level Inorganic 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 AS and A Level Inorganic Chemistry essays

  1. Peer reviewed

    Deducing the quantity of acid in a solution

    5 star(s)

    at eye level and ensure the bottom of meniscus reached the graduation mark. Also, when doing the titration, we rinsed all the equipment three times after using it with the proper solution. This should give us more precise results when reaching the endpoint.

  2. Peer reviewed

    Investigation to determine the Relative atomic mass of Li

    5 star(s)

    - Mass of Li = 0.12g - No Moles of Li = 0.00416 mol - Relative atomic mass = mass/no moles - 0.12/0.00416 = 28.85 However since only 0.03g of Lithium was used, the result for 25 cm3 will represent 4x.

  1. effects Concentration and Temperature on the Rate of Reaction

    43.1 42.6 42.8 42.76 0.0234 25 28.8 28.3 27.9 28.1 28.6 28.34 0.0353 30 19.6 19.8 19.3 19.5 19.4 19.52 0.0512 35 12.1 11.5 11.9 11.7 11.9 11.82 0.0846 40 5.1 5.6 4.9 5.2 5.4 5.24 0.1908 From Graph 5 on the next page, it is clear that there is

  2. Investigating the enthalpy change of different fuels when combusted.

    In this experiment there is only 1 dependant variable for each alcohol and that is the change in mass of the spirit burner + alcohol + lid. This will allow us to calculate the enthalpy change and therefore how much energy is required to heat up water through 20�C.

  1. The periodic table

    30 Ag 37 Cs 44 Tl 53 Gl 3 Mg 10 Ca 17 Zn 25 Sr 31 Cd 34 Ba/V 45 Pb 54 Bo 4 Al 11 Cr 18 Y 24 Ce/La 33 U 40 Ta 46 Th 56 C 5 Si 12 Ti 19 In 26 Zr 32 Sn

  2. Chemistry determination of RAM of lithium

    As accurate as can be expected from a classroom experiment. Less accuracy would result in inaccurate results, inconsistency and therefore unreliable results Using a gas syringe to collect hydrogen This method may be more effective as volume of oxygen can be measured to 0.5 cm�.

  1. relative atomic mass of lithium

    of moles = 0.00378 x 4 = 0.01512 moles = 0.0151 moles (3 significant figures) I will now calculate the Relative atomic mass of lithium using the number of moles of lithium and the mass of lithium used. Relative atomic mass = Mass of lithium Number of moles = 0.08g 0.0151 moles = 5.298013245 = 5.3 (2 significant figures)

  2. An investigation into the behaviour of mono-di-tri protic acids with a pure metal.

    most appropriate and adequate method to measure the rate of the reaction, and ultimately obtain the order for the reaction as well as an overall rate equation. The other method is known as 'initial rates' where in this particular reaction a large excess of acid would be used so that

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