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

Essay by sy124 November 2003

The Synthesis and Determination of Empirical Formula for Magnesium Oxide

Aim:

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)

16.04716.21416.294

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 ÃÂ±0.002 g

- 16.047ÃÂ± 0.002 g

0.167 ÃÂ± 0.004 g

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

16.294 ÃÂ±0.002g

- 16.214 ÃÂ±0.002g

0.0800ÃÂ±0.004

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

=0.167ÃÂ±2 % g

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

=0.0800ÃÂ±5% g

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

=0.00500 ÃÂ±5%mol

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

=0.00687ÃÂ±2%mol

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

=1.37ÃÂ±7%mol

=1.37ÃÂ± (7*1.37/100)

=1.37ÃÂ±0.1

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

=1.00ÃÂ±10%

=1.00ÃÂ±(10*1.00/100)

=1.00ÃÂ±0.1

9.Empirical Formula= Mg1.37ÃÂ±0.1O1.00ÃÂ±0.1

=MgO

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 OÃÂ± uncertainties (g)Mass of Mg ÃÂ± uncertainties(g)Number of Mole ÃÂ± % of uncertainties Relative...