Question

A small atomic bomb releases energy equivalent to the detonation of 14,000 tons of tnt; a ton of tnt releases 4 ? 109 j of energy when exploded. using 2 ? 1013 j/mol as the energy released by fission of 235u, what mass of 235u undergoes fission in this atomic bomb?

Answer 1

We are given
energy released by a small atomic bomb = 14000 tons of TNT
1 ton TNT = 4x10^9 J
2 x 10^13 J energy released by 1 mole of 235U
The mass 235U that undergoes fission in this atomic bomb is
14000 tons TNT x (4 x 10^9 J / 1 ton TNT) x (1 mol 235U / 2 x 10^13 J) x (235 g 235U / 1 mol 235U)
= 658 g of 235U