An interpenetrating primitive cubic structure like that of CsCl with anions in the corners has an edge length of 664 pm. If the ratio of the ionic radius of the cation to the ionic radius of the anion is 0.840, what is the ionic radius of the anion

the ionic radius of the anion

Explanation:

From the diagram shown below :

The anion is located at the corners

The cation is located at the body center

The Body diagonal length =  

∴

Given that :

  (i.e the  ratio of the ionic radius of the cation to the ionic radius of

                 the anion )

Also ; a =  664 pm

Then :

Therefore,  the ionic radius of the anion

Spontaneity tell us the direction of the reaction, but not how fast it goes. gibbs free energy brings together enthalpy, entropy and temperature in one easy formula. g = h - ts. and, finally the sign of delta g is always negative for a spontaneous reaction.

What? i don’t understand