Titanium has an HCP unit cell for which the ratio of the lattice parameters c/a is 1.58. If the radius of the Ti atom is 0.1445 nm, calculate the density of Ti and compare it with the literature value of 4.51 g/cm3 . The atomic mass of titanium is 47.87 g/mol.

4.81 g / mol

Explanation:

Given :

Titanium has an HCP unit cell

Radius of titanium, R = 0.1445 nm

Unit cell volume,

But for Ti, c/a = 1.58

           So, c  = 1.58 a

And a = 2R or c = 3.16 R

Density of Ti (theoretical),

For HCP, n = 6 atoms per unit cell and atomic mass = 47.87 g/mol

  = 4.81 g/mol

This is the theoretical density of titanium.

The value given in literature is 4.51 g/mol

a. energy is absorbed in the reaction.

if in a given reaction the energy of products is greater than the energy of reactants it means that reaction is endothermic and during the reaction, the energy is absorbed by reactants. in an endothermic reaction, the products have more stored chemical energy than the reactants. and in this reaction the reactants are more stable than products before the compounds with less energy are always more stable.