Explain how vacancies are introduced in an ionic solid when a cation of higher valency is added as an impurity in it.

In case of ionic solids the opposite ions balance the charge of each other. The amount of cations and anions is mostly same in case of charge.

But when we add a cation with higher charge , the cation can replace the other cations in lattice and can create vacancy because to balance the charge, the cation with lower charge will leave the lattice.

for example if we add Sr²+ in NaCl crystal . The Sr²+ ion will replace two Na+ ions . To balance the charge of Sr²+ , two Na+ cations will leave the place and create vacancy.

NaCl crystal without impurity
Formation of vacancy on addition of Sr²+

Published by Ankush Sharma

I am M.Sc (chemistry ) from Punjabi University Patiala. I am a science teacher with expertise in chemistry, with 8 years of experience in teaching. Writing and blogging is my hobby, I write whenever I am free. I am constantly working on creating a new and easy way of learning the tough things in an effective way. I am constantly working to make authentic and reliable information to be shared with my students and widen the horizons of knowledge.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.

%d bloggers like this: