Question

uranium has two isotopes of masses 235 and 238 units.If both are present in Uranium hexafluoride gas which would have the larger average speed?If atomic mass os fluorine is 19 units,estimate the percentage difference in speeds at any temperature.​

Answer 1

Hey dear,

● Answer -
Velocity(U235) > Velocity(U238)
% diff in speeds = 0.43%


● Explanation -
# Given -
M1 = 235 + 6×19 = 349 g/mol
M2 = 238 + 6×19 = 352 g/mol

# Solution -
Average speed of a gas at fixed temperature ia given by -
vavg = √(3nRT/2)

Ratio of average speeds of given gases is calculated by -
v1/v2 = √(M2/M1)
v1/v2 = √(352/349)
v1/v2 = 1.0043

Percentage difference in speeds -
% diff = (1.0043-1)×100%
% diff = 0.43%


Hence, U235 gas is faster than U238 gas by 0.43 %.

Hope this helped ...