Question

What would be the mass in grams of 0.300 moles of the ionic compound formed when magnesium metal reacts with oxygen

Answer 1

Balanced Equation for reaction between Magnesium and Oxygen:

2Mg + O₂ --> 2MgO

Molar Mass of MgO is the atomic masses listed on the periodic table for the two elements Magnesium and Oxygen. Magnesium's molar mass is 24g/mol, and Oxygen's molar mass is 16g/mol. So MgO's molar mass would be 24 + 16 = 40g/mol.

The equation to find moles is:

`moles \ = \ (mass)/(molar \ mass)`

So if we rearrange this equation to find for mass:

`mass = moles \ * \ molar \ mass`

So you have to multiply 0.300 moles by 40, which gives you 12g

Meaning the mass of Magnesium Oxide is 12g.