Subject: Physical Chemistry · Chapter: Surface Chemistry · Topic: Surface Chemistry – General · Exam: CSIR-NET JUNE 2018 · Marks: 2 · Difficulty: Medium
In fission of ${ }^{\mathrm{235}} \mathrm{U}$ atom the energy released is 200 MeV . In one day fission of $1 \mathrm{kg}^{235} \mathrm{U}$ will give power (in MW) approximately
(a)550
(b)650
(c)950
(d)1250
Answer
Answer (as printed): D
Explanation
Units: $1\,\mathrm{MeV}=10^{6}\,\mathrm{eV}$, $1\,\mathrm{MW}=10^{6}\,\mathrm{W}$, $1\,\mathrm{eV}=1.6\times10^{-19}\,\mathrm{J}$.One $^{235}U$ fission releases $200\,\mathrm{MeV}$ of energy.Number of atoms in 1 kg of $^{235}U$: $N=\dfrac{1000\,\mathrm{g}}{235}\times N_{A}\approx2.56\times10^{24}$ atoms.