How many magnesium atoms are in magnesium nitride

As important…. Your physics assignments can be a real challenge, and the due date can be really close — feel free to use our assistance and get the desired result. Be sure that math assignments completed by our experts will be error-free and done according to your instructions specified in the submitted order form. Our experts will gladly share their knowledge and help you with programming projects. General Chemistry. Need a fast expert's response? Place free inquiry.

Calculate the price. Learn more about our help with Assignments: Chemistry. Comments No comments. Be the first! Thank you! The question then arises whether any nitride is ever formed. In researching this, we found that there is disagreement even in the advanced level text books about some of the physical properties of Mg 3 N 2. For example, it is variously described as colourless, 1,2 yellowish green, 3 yellow-green to yellow-orange 4 and yellow 5 while Bickley and Greg 6 describe both grey and yellow forms.

Further, various melting or decomposition points are given. Belin 7 notes that Mg reacts preferentially with traces of O 2 during the reaction of Mg in N 2. There is agreement, however, that Mg 3 N 2 can be synthesised by direct reaction of the elements and the consensus is that the reaction on a lab scale completes in four to five hours at — o C.

Perhaps this is the seed of a great demonstration! About 1 g of Mg ribbon was weighed and heated gently at first then strongly in a partially covered crucible for 15 minutes and cooled. No yellow or greenish colour could be seen in the product and weighing the product gave a result consistent with the pure MgO being the product. In the texts, it is commonly asserted that MgO which is formed by the combustion of Mg in air may be contaminated with Mg 3 N 2.

This is not unreasonable given that the temperature of burning Mg is much greater than the o C noted above and although Mg 3 N 2 burns in O 2 to form MgO, the rapid cooling of the ash might preserve any nitride present.

To test this, about 20 cm of Mg ribbon was ignited and burned over an asbestos pad while being held by crucible tongs. Some of the reaction product was lost as white smoke but much solid ash was collected in a pile on the pad.

The ash that fell to the pad and cooled was heterogeneous, being mostly pure white but with some dark grey material also present. It was wetted thoroughly with a few drops of water and an attempt was made to detect ammonia eq. None was found. Further, the dark matter remained, apparently unchanged. In order to see if an O 2 depleted and therefore N 2 enriched atmosphere might give some evidence for the production of Mg 3 N 2 an experiment was performed as described above except that the crucible was completely closed by the lid, and the crucible was heated for one hour.

It was expected that as the oxygen was consumed by reaction with the Mg that the atmosphere in the crucible would asymptotically become richer in nitrogen and any reaction between the Mg and N 2 would be evident. There was almost no reaction except for a small amount of white ash which had no apparent reaction with water. Clearly, O 2 was effectively excluded from the crucible, and the remaining N 2 did not react with the Mg ribbon.

Given that no evidence of Mg 3 N 2 formation could be found, it appears that the hydration step is not necessary and only makes the experiment more difficult. We use the most common isotopes. This is how to calculate molar mass average molecular weight , which is based on isotropically weighted averages. This is not the same as molecular mass, which is the mass of a single molecule of well-defined isotopes.

For bulk stoichiometric calculations, we are usually determining molar mass, which may also be called standard atomic weight or average atomic mass.

Using the chemical formula of the compound and the periodic table of elements, we can add up the atomic weights and calculate molecular weight of the substance. If the formula used in calculating molar mass is the molecular formula, the formula weight computed is the molecular weight.