The Synthesis and Determination of Empirical Formula for Magnesium Oxide
To determine the empirical formula for magnesium oxide.
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
- 16.214 ±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%)
5.Mole O = (0.0800±5%g) /(15.999g/mol)
6.Mole Mg = (0.167±2% g)/(24.305g/mol)
7.Relative ratio of Mg = 0.00687/0.00500 ±(2 % +5%)mol
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 ratio ±...
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