This is lab report about The Synthesis and Determination of Empirical Formula for Magnesium Oxide.

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The Synthesis and Determination of Empirical Formula for Magnesium Oxide


To determine the empirical formula for magnesium oxide.

Data Collection:

Table 1 Mass of empty crucible, crucible + Mg (roughly 1cm pieces of a 15-cm piece of magnesium ribbon), and crucible +MgxOy. (mass measured with an analytical balance). The mass of crucible + MgxOy was obtained after a continuous process of heating, letting cool, heating with water enough to immerse the content and letting cool of the Mg.

Mass of Empty crucible (g)Mass of Crucible + Mg (g)Mass of Crucible +MgxOy (g)


Uncertainty of analytical balance = + 0.002

*Note that because we are uncertain if Mg has completely reacted with O2 in the first heating, if all the Mg have reacted with O2 instead of N and if the water added has completely vaporized in the second heating(with water), the data and the following calculations may not be as accurate.

Data Presentation and Procession:

1.mass of crucible + Mg - mass of empty crucible =Mass of Mg

16.214 ±0.002 g

- 16.047± 0.002 g

0.167 ± 0.004 g

2.mass of crucible + MgxOy -mass of crucible +Mg = mass of O

16.294 ±0.002g

- 16.214 ±0.002g


3.mass of Mg =0.167±(0.004/0.167*100%)

=0.167±2 % g

4.mass of O = 0.0800±(0.004/0.0800*100%)

=0.0800±5% g

5.Mole O = (0.0800±5%g) /(15.999g/mol)

=0.00500 ±5%mol

6.Mole Mg = (0.167±2% g)/(24.305g/mol)


7.Relative ratio of Mg = 0.00687/0.00500 ±(2 % +5%)mol


=1.37± (7*1.37/100)


8.Relative ratio of O = 0.00500/0.00500 ±(5%+5%)




9.Empirical Formula= Mg1.37±0.1O1.00±0.1


Table 2 Mass and relative ratio of Mg and O and calculated empirical formula for magnesium oxide as determined by its relative ratio.

Mass of O± uncertainties (g)Mass of Mg ± uncertainties(g)Number of Mole ± % of uncertainties Relative...