Question

Write reactions of group IIA elements with.
$1$. Water
$2$. Oxygen
$3$. Hydrogen
$4$. Chlorine.

Answer 1

The reactions of group IIA elements are as given below.
1. Water
Alkaline earths (except Be) react with water to liberate hydrogen.
$M+2H_{2}O\to M(OH{)}_2+H_2\uparrow$
(M$=$ Mg, Ca, Sr, Ba)
2. Oxygen:
Be, Mg and Ca form oxides
$2M+O_2\stackrel{\Delta }{\to }2MO$
(M$=$Be, Mg and Ca)
Ba, Sr and Ca forms peroxides
$M+O_2\to M{O}_2$
(M$=$Ba, Sr ro Ra)

3. Hydrogen
Alkaline earths (except Be) combine directly with hydrogen to form hydrides.
$M+H_2\stackrel{\Delta }{\to }M{H}_2$
(M$=$Mg,Ca,Sr or Ba)
4. Chlorine.
Alkaline earths combine with chlorine at high temperature to form chlorides.
$M+C{l}_2\to MC{l}_2$