In the removal of water hardness, permutit is regenerated with a strong solution of
-
A.
NaOH -
B.
Na(_3)SO(_4) -
C.
Na(_3)CO(_3) -
D.
NaCl
Explanation
Permutit is also known as zeolite. When a sample of hardwater is percolated through a bed of powdered permutit the following base exchange reaxtion takes place making the sample of water soft.
2Na-permutit + Ca(^{+2}) → Ca (permutit)2 + 2Na(^{+}).
The ions Ca(^{+2}) causing hardness to water are absorbed by permutit releasing releasing Na(^{+}) and hardness is removed. When all the Na site in permutit is replaced by Ca(^{+2})
There is an explanation video available below.