Question

How much MgO is made when 12Kg of Mg is completely burned in air?

Answer 1

Answer:

Mass = 20,000 g  

Explanation:

Given data:

Mass of MgO formed = ?

Mass of Mg react = 12 Kg (12 Kg × 1000/1 Kg = 12000 g)

Solution:

Chemical equation:

2Mg + O₂     →   2MgO

Number of moles of Mg:

Number of moles = mass/molar mass

Number of moles = 12000 g/ 24 g/mol

Number of moles = 500 mol

Now we will compare the moles of Mg and MgO.

             Mg          :           MgO

             2             :           2

            500         :          500

Mass of MgO:

Mass = number of moles × molar mass

Mass = 500 mol × 40 g/mol

Mass = 20,000 g