Question

A certain element, M, is a main-group metal that reacts with chlorine to give a compound with the chemical formula MCl₂ and with oxygen to give the compound MO.

(a) To which group in the periodic table does element M belong?

(b)The chloride contains 44.7% chlorine by mass. Name the element M.

Short answer

a) The element M belongs to the alkaline earth metal group.

b) The name of the element M is Sr.

Step-by-step solution

Element

An element is a little substance that is only in its pure state and cannot be broken up into smaller components.

Main group element: Elements that are part of the S and P blocks are referred to as the major group elements. These elements come in a variety of groups, including metals, non-metals, semi-conductors, and others.

Components of the main group M that react with Cl to produce MCl₂ and with O to produce MO;

a) A metal will belong to the alkaline earth metal group, or the second group in the modern periodic table, if it reacts with Cl to produce MCl₂ and with O to produce MO.

The Name of the Element

The molecule is MCl₂ and Cl₂ makes up 44.7% of the compound's total mass, so M will acquire 100 - 44.7 = 55.3%. Cl₂ has a molecular weight of is 71 g/mol. We can find the molecular weight of M i.e 44.7% of Cl_{2 has a}molecular weight of 71 g/mol, so 55.3% of M will have,

$\frac{55.3\times 71}{44.7}=87.6g/mol$

So the molecular weight of Sr is 87.6 g/mol and the compound is SrC₂.