Question

(a)
Write equations for the reactions of ​
(i) iron with steam.

(b)
(ii) calcium and potassium with water.

Answer 1

(a)
When a metal reacts with steam then the products formed are metal oxide and hydrogen gas.​

Similarly, iron reacts with steam to form iron oxide with the evolution of hydrogen gas. ​

Chemical equation: ​

$3Fe\left(s\right)+4H_{2}O\left(g\right)\to F{e}_3{O}_4\left(s\right)+4H_2\left(g\right)$

(b)

Calcium reacts with water to form calcium hydroxide and hydrogen gas.​

Chemical equation:
$Ca\left(s\right)+2H_{2}O\left(I\right)\to Ca\left(OH{)}_2\right(aq)+H_2(g)$

Potassium reacts vigorously with water, to form potassium hydroxide and this reaction is highly exothermic.​

Chemical equation:
$2K\left(s\right)+2H_{2}O\left(I\right)\to 2KOH\left(aq\right)+H_2\left(g\right)+\text{heat}$