Solid StatehardNUMERICAL

In a crystalline compound, atoms of element A form a face-centered cubic (FCC) lattice. Atoms of eleSolid State Chemistry Question

Question

In a crystalline compound, atoms of element A form a face-centered cubic (FCC) lattice. Atoms of element B occupy all the available octahedral voids and exactly half of the available tetrahedral voids. What is the precise numerical ratio of B atoms to A atoms present in the compound?

Answer: 2

💡 Solution & Explanation

A atoms form the FCC lattice, yielding an effective number of A atoms = $4$. In FCC, there are 4 octahedral voids and 8 tetrahedral voids. B occupies all 4 OVs and half of the TVs ($8/2=4$). Total B atoms = $4 + 4 = 8$. The ratio of B atoms to A atoms is $8 : 4 = 2$.

💬
Still have doubts about this question?
Send it to our AI chemistry tutor on WhatsApp — gets answered in minutes
Ask on WhatsApp →

Practice 22,000+ questions like this

AI-adaptive practice, video lectures, and full IChO (Chemistry Olympiad) content — all in one place.

JEE Advanced · JEE Mains · NEET · IChO · AP Chemistry