JEE Advanced
- Exam
- JEE Advanced
- Subject
- Chemistry
- Chapter
- Solid State
JEE Advanced · Chemistry · Solid State
Titanium crystallizes in a face centred cubic lattice. It reacts...
Titanium crystallizes in a face centred cubic lattice. It reacts with C or H interstitially, by allowing atoms of these elements to occupy holes in the host lattice. Hydrogen occupies tetrahedral holes, but carbon occupies octahedral holes.
(a) Predict the formula of titanium hydride and titanium carbide formed by saturating the titanium lattice with "foreign" element.
(b) What is the maximum ratio of "foreign" atom radius to host atom radius that can be tolerated in a tetrahedral hole without causing a strain in the host lattice?
Correct answer
0.225
Step-by-step solution
(a) There are 4 atoms per unit cell and 8 tetrahedral sites per unit cell.
So, the ratio of atoms to tetrahedral sites
So, the formula would be
For carbide,
Since carbon occupies octahedral holes
So, ratio of octahedral hole to atom
The formula of carbide is TiC
(b) Since for tetrahedral hole, the limiting ratios, radius ratio
to 0.414
Without causing a strain in the host lattice, i.e.