Question

$2MgO + {O_2} \to 2MgO$ , Calculate how much oxygen required combust 10 moles of magnesium from the given equation

Answer 1

Hint: Magnesium and oxygen react and form magnesium oxide. This equation compares with stoichiometric coefficient. For combusts, we required here 2 mole of Mg and 1 mole of O. The number of moles depend on the oxidation state of elements and combination of reactants make a product.

Complete step by step answer:
The equation for magnesium oxide is given as below,
 $2MgO + {O_2} \to 2MgO$
This reaction occurs stoichiometric coefficient which is the reaction between mass of products and reactants in chemical reaction.
We must know the oxidation state of reactants to get product. To balance the equation, we take moles of the reactants. Here we see that the oxidation state of Mg is +2 and the oxidation state of O is -2. The equation takes 2 mole of Mg because the oxygen is in ${O_2}$ form so it contains -4 oxidation state that is the reason to take 2 mole of Mg.
1 mole of oxygen required is 2 mole of oxygen.
For burn, if we take 10 mole of Mg, the mole of oxygen is 5.
So here we find the amount of oxygen to burn 10 moles of magnesium is,
=mass of oxygen $ \times $ number of moles of oxygen required to burn
 \[
   = 32 \times 5 \\
   = 160{\text{ }}gram \\
 \]

Hence, to combust 10 mole of magnesium, we required 160 gm of oxygen.

Note:
The combustion of elements depends on the oxygen and heat. The element reacts with oxygen during the combustion process. To find the amount of oxygen, we must know the number of moles of oxygen and molar mass of oxygen and finally we take the amount of weight which is required to burn elements.