2007-03-18 02:40:28 · 3 answers · asked by thina a 1 in Science & Mathematics ➔ Chemistry
Density = mass / volume
Use dimensions of unit cell and mass of ions in unit cell to calculate the density.
2007-03-18 02:50:20 · answer #1 · answered by physandchemteach 7 · 0⤊ 0⤋
NaCl has rock salt structure or FCC (face centred cubic) structure so Z =4
according to the formula
D = M x Z/ No x a^3
where D= density in grams/cm^3
No = avogadro's constant
a=edge length in (cm)
M= is the given mass.
Z= no.of atoms in a unit cell
VALUES OF "Z" FOR DIFFERENT STRUCTURES
Z=4 face centred cubic lattice or simple cubic
Z=2 for body centred cubic lattice in case of element
Z=1 for body centred cubic lattice in case of compound
2007-03-18 12:15:39 · answer #2 · answered by Anonymous · 0⤊ 0⤋
density of such a unit cell which has cl ions on octahedral voids and na on all latice sites of FCC .
density = M*Z/N*V
first calculate volume then apply in formula in which Z = 6
2007-03-18 10:00:04 · answer #3 · answered by abhi19 1 · 0⤊ 0⤋