# NEET Chemistry The Solid State Questions Solved

BOARD

An element with density 2.8 g cm-3 forms a f.c.c. unit cell with edge length 4$×$10-8 cm. Calculate the molar mass of the element.

(Given : NA = 6.022$×$1023 mol-1)

Using formula : $\rho$ = $\frac{Z×M}{{a}^{3}×{N}_{0}}$ for f.c.c, Z = 4

M = $\frac{\rho ×{a}^{3}×{N}_{0}}{Z}$

$\therefore$ M =

$\therefore$ Molar mass, M = $\frac{1079.1424}{40}$ = 26.978 g/mol

Difficulty Level:

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