Question

An unknown sample weighing 1.5 g was found to contain only $Mn$ and $S$. The sample was completely reacted with oxygen and it produced 1.22 g of $Mn\left(II\right)$ oxide and 1.38 g of $S{O}_3$. What is the simplest formula for this compound?

• A. $M{n}_{2}S$
• B. $MnS$
• C. $M{n}_2{S}_3$
• D. None of these

Answer 1

The correct option is B $MnS$

Weight of $MnO=1.22g$

Weight of $S{O}_3=1.38g$

Weight of Manganese sulphide= $1.5g$

Let us suppose the formula to be $MnS$

$MnS+2O_2⟶MnO+S{O}_3$

$87g$ $71g$ $80g$

So, $MnS:MnO:S{O}_3$

$87$ : $71$ : $80$

or, $87/58$ : $71/58$ : $80/58$

or, $1.5:1.22:1.38$ given values

Hence, the simplest formula for the compound is $MnS$ .