A metal M react with sulphur ro form MS. If 3.6g of M reacts with 0.09mol of sulphur to form MS . what is the name of M.

Calcium

Explanation:

We must first put down the reaction equation as this will serve as a guide in solving the question.

M(s) + S(s) > MS(s)

According to the reaction equation; 1 mole of metal reacts with 1 mole of sulphur. Hence 0.09 moles of sulphur reacts with 0.09 moles of metal.

Now recall that;

Number of moles (n) = mass(m)/ molar mass(M)

Since

mass of metal reacted= 3.6g

Number of moles of metal= 0.09 moles

Then;

Making molar mass of metal the subject of the formula;

Molar mass of metal = mass of metal / number of moles of metal

Molar mass of metal = 3.6g /0.09 moles

Molar mass of metal= 40 gmol-1

The metal having a molar mass of 40gmol-1 is calcium, therefore the metal is calcium.