Question

The density of solid Argon is 1.6 ml at - 233°C. If the Argon atom is assumed to be sphere of radius 1.5 × 10^-8 cm, then the ______ % of solid Argon is apparently occupied.

[Take : N_A = 6 × 10²³, Atomic mass of Ar = 40]

Options

• 10

• 3

• 5

• 1

Answer 1

The density of solid Argon is 1.6 ml at - 233°C. If the Argon atom is assumed to be sphere of radius 1.5 × 10^-8 cm, then the 3 % of solid Argon is apparently occupied.

Explanation:

V = `40/1.6` = 25

V = `4/3 pi"R"^3 xx "N"_"A"`

V `= 4/3 xx 22/7 xx (1.5)^3 xx 10^-24 xx 6 xx 10^23`

V = 8.4 ml

% occupied = `8.4/25 xx 100` = 33.6

`33.6/10 = 3.36 ~~ 3`