Exams › NEET › Chemistry

CsBr crystallises in a body-centred cubic lattice. The unit cell length is 436.6 pm. Given that the atomic mass of Cs=133 and that of Br=80 amu and Avogadro number being 6.02 × 1023 mol−1 the density of CsBr is

1. 0.425 g/cm3
2. 8.25 g/cm3
3. 4.25 g/cm3
4. 42.5 g/cm3

Correct answer: 4.25 g/cm3

Solution

The density of a body-centred cubic lattice is calculated using the formula: Density = (Z × M) / (a³ × N_A), where Z = 2 for BCC, M = molar mass of CsBr (133 + 80 = 213 g/mol), a = 436.6 pm = 436.6 × 10⁻¹⁰ cm, and N_A = 6.02 × 10²³ mol⁻¹. Substituting values, density = (2 × 213) / ((436.6 × 10⁻⁸)³ × 6.02 × 10²³) ≈ 4.25 g/cm³.

Related NEET Chemistry questions

• Which one of the following statements about the zeolites is false?
• Glass is a:
• When electrons are trapped into the crystal in anion vacancy, the defect is known as
• On doping Ge metal with a little of In or Ga, one gets
• For two ionic solids CaO and KI, identify the wrong statement amongst the following:
• An example of a double salt is

⚔️ Practice NEET Chemistry free + battle 1v1 →