Question

$1.2$ g of Mg (atomic mass $=24$ amu) will produce MgO equal to :

• A. $0.05$ mol
• B. $40$ g
• C. $40$ mg
• D. $4$ g

Answer 1

The correct option is A $0.05$ mol

As reaction is as follows:

$Mg+\frac{1}{2}{O}_2\to MgO$

It means 1 mol of $Mg$ reacts to give 1 mol of $MgO$.

Number of moles of Mg in 1.2 g $=\frac{1.2}{24}=0.05mol$ of $Mg$.

Therefore, the number of moles of $MgO=0.05mol$

Hence, option A is correct.