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

The emperical formula of MgO

Extracts from this document...


The Empirical Formula of Magnesium Oxide Data collection: This table shows the mass of different chemicals: Chemicals Mass/g + 0.01 crucible lid 38.12 crucible lid+ Magnesium 38.30 crucible lid + contents after heating 38.40 Table (1): Raw data Uncertainties: 1. balance +/-0.01 Data processing and presentation: Quantity Mass+ the uncertainty Magnesium 38.30- 38.12=0.18+0.1 oxygen 38.40- 38.30=0.10+0.1 number of moles of Mg 0.18/24.31=0.00699 number of moles of oxygen 0.10/16=0.00625 Table (2) Mass of Mg= (the mass of crucible lid +Mg) - (the mass of crucible lid) = 38.30- 38.12= 0.18 Mass of Oxygen= (the mass of crucible lid + contents after heating) - (the Mass of crucible lid+ Magnesium) =38.40- 38.30=0.10 -3 Number of moles of Mg=0.18/24.31= 6.7 X10 moles Number of moles of oxygen= 0.10/16.00 = 6.3 X10 moles Ratio Mg/O =0.00699/ 0.00625 =1.11+0.1 The actual value of Mg/O=1.00 The experimental empirical formula Mg O 6.7 X10 6.3 X10 6.3 X10 6.3 X10 Mg O 1.1 1 Magnesium oxide is made up of a ratio by mass of approximately 1:1 Magnesium to Oxygen, giving up an empirical formula of MgO. ...read more.


The theoretical empirical formula for Magnesium Oxide was Mg2.4O while the experimental empirical formula was MgO. Because the theoretical mole ratio differed from the experimental mole ratio, there is a mole ratio percent error. To find the mole ratio percent error, the Oxide as 2 magnesium atoms per 2 oxygen atoms. This theoretical ratio is 2:2which equals 1:1. From the Experimental empirical formula, the experimental percent composition was determined to be 65.2% magnesium in the magnesium oxide and 34.5%oxygen in the magnesium oxide. These numbers differ from the theoretical percent composition, as the theoretical percent composition was 60.3% magnesium and 39.7%oxgyen. The percent error in the experimental percent compositions for both magnesium and oxygen were calculated using the theoretical percent compositions for magnesium and oxygen, and the experimental percent compositions for these elements, and then plugging these numbers into the percent error formula. The percent error for magnesium was 8.6%, with the percent error of the oxygen being 13.1 %.( Refer to percent error under results for complete calculations) ...read more.


Also, although the crucible was taken off the flame only when the magnesium inside looked fully oxidized, and therefore altered the ratio of magnesium to oxygen in the resulting magnesium oxide, because of the amount of magnesium which was not chemically combined with oxygen. Improvements may be made to the lab to lessen the margin for error. The shape of the metal could be standardized to lessen the possibility for leftover unoxidized magnesium. If the magnesium was in smaller particles, the greater surface area might allow a more complete oxidation process since there would be more surface area for the oxygen to chemically react with. Also a way to ensure complete oxidation of the magnesium would be beneficial. Although stirring the magnesium oxide to check for any unoxidized magnesium would probably remove some magnesium oxide on the stirring instrument, maybe the crucible could simply be left on the flame for an additional period of time to lessen the chance for unoxidized magnesium. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our International Baccalaureate 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 International Baccalaureate Chemistry essays

  1. Experiment - The Empirical Formula of Magnesium Oxide

    =16.00g/mol, the masses has already been calculated above. Thus, substitute the values into the formula: n(Mg)=0.086/24.31=3.5*10^-3mol n(O)=0.057/16.00=3.6*10^-3mol The results gained were rounded up to 3 decimals so that they are consistent with the absolute uncertainties. Percentage uncertainties associated with masses and number of moles Due to division was employed; the absolute uncertainties of the mass of each element

  2. An Experiment to Determine the Empirical Formula of Lead Iodide

    g Moles of lead x 10-4 Ratio Lead : Iodine 1 0.141 1.11 0.151 7.29 1:1.5 2 0.158 1.25 0.152 7.34 1:1.7 3 0.133 1.05

  1. Lab Experiment : The change in mass when magnesium burns. (Finding the empirical formula ...

    + 0.0001= 32.9232g Mass of magnesium inside crucible with the lid ( in grams) + 0.0001 =33.1472g Final mass of (MgO) inside crucible with lid in grams + 0.0001=33.2711g Mass of MgO inside crucible with lid in grams after �heating to constant mass`=33.2605g Processed Data: Percentage uncertainty= 0.04% 1.Mass of magnesium (in grams)

  2. Dissolved Oxygen in water

    Controlled Variables: The controlled variables in the experiment would be the dissolved oxygen kit which means that we will be using the same glass bottle, same chemicals and the same syringe in order to keep it a fair test. We will control this variable simply by making sure that we use the same dissolved oxygen test kit.

  1. Enthalpy of Combustion of Alcohols Lab

    (4.186 Jg-1k-1) (11.5 k) Q = 4813.9 J Q = 4.81 kJ Step 3: Calculating the enthalpy of combustion ?HC = Q/mol ?HC = 4.81kJ 0.0480mol = 100 kJ/mol However it is exothermic, that is why it has to be negative = - 100 kJ/mol Step 4: Calculating the uncertainties Uncertainty for mass of alcohol combusted = (0.02g/1.53g)

  2. Finding thr Percentage Composition of Magnesium Oxide

    The crucible was removed and put aside to cool. The mass of the crucible and contents were weighed and recorded, then left for Part B. Part B: Correcting for Magnesium Nitride Using tongs, the cooled crucible was transferred to the bench top.

  1. To determine the standard enthalpy of formation of Magnesium Oxide using Hess Law.

    The container claimed to contain MgO with only trace amounts of impurities. Dependent Variables: 1. Maximum temperature reached: Temperature of the solution was recorded using the same thermometer each time so that no additional systematic errors are introduced. Controlled Variable Reason for controlling Method of Controlling Calorimeter Using different calorimeters

  2. Finding the empirical formula of magnesium oxide

    percentage of magnesium and oxygen in MgO m1=0.30g mass of MgO(m1+m5), (0.30+0.17)g=0.47g Percentage of Mg, x100%=63.83% Percentage of O, x100%=36.17% m1=0.30g mass of MgO(m1+m5), (0.30+0.17)g=0.47g Percentage of Mg, x100%=63.83% Percentage of O, x100%=36.17% Theoretical percentage of magnesium and oxygen in MgO R.M.M of MgO= 40.31gmol-1 R.A.M of Mg=24.31gmol-1 R.A.M of

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