All Exams Test series for 1 year @ ₹349 only
Question

In the fission reaction

\(\rm { }_{92}^{235} U +{ }_0^1 n \rightarrow{ }_{56}^{140} Ba +{ }_{36}^{93} Kr +3{ }_0^1 n\)

for given masses of 235U (235.0439 amu), 10Ba (139.9106 amu), 93Kr (92.9313 amu) and n (1.00867 amu), and 1 amu (931.494 MeV/e2), the energy released is

The correct answer is

172.0 MeV

Fission Reaction Energy Release Calculation

In a nuclear fission reaction, energy is released because the total mass of the products is less than the total mass of the reactants. This difference in mass is called the mass defect ($\Delta m$), which is converted into energy according to Einstein's mass-energy equivalence principle, \(E = \Delta m c^2\).

The given fission reaction is:

\( { }_{92}^{235} U +{ }_0^1 n \rightarrow{ }_{56}^{140} Ba +{ }_{36}^{93} Kr +3{ }_0^1 n \)

We are given the masses of the involved particles:

  • Mass of \( { }^{235}U \): 235.0439 amu
  • Mass of \( { }^{140}Ba \): 139.9106 amu
  • Mass of \( { }^{93}Kr \): 92.9313 amu
  • Mass of \( n \): 1.00867 amu

We are also given that 1 amu corresponds to 931.494 MeV/\(c^2\).

Calculating Total Mass of Reactants

The reactants are one \( { }^{235}U \) atom and one neutron (\( n \)).

Total mass of reactants = Mass(\( { }^{235}U \)) + Mass(\( n \))

Total mass of reactants = 235.0439 amu + 1.00867 amu

Total mass of reactants = 236.05257 amu

Calculating Total Mass of Products

The products are one \( { }^{140}Ba \) atom, one \( { }^{93}Kr \) atom, and three neutrons (\( 3n \)).

Total mass of products = Mass(\( { }^{140}Ba \)) + Mass(\( { }^{93}Kr \)) + 3 \(\times\) Mass(\( n \))

Total mass of products = 139.9106 amu + 92.9313 amu + 3 \(\times\) 1.00867 amu

Total mass of products = 139.9106 amu + 92.9313 amu + 3.02601 amu

Total mass of products = 235.86791 amu

Calculating Mass Defect

The mass defect (\(\Delta m\)) is the difference between the total mass of reactants and the total mass of products.

\(\Delta m\) = Total mass of reactants - Total mass of products

\(\Delta m\) = 236.05257 amu - 235.86791 amu

\(\Delta m\) = 0.18466 amu

Calculating Energy Released

The energy released (\(E\)) is calculated using the mass defect and the given energy equivalent of 1 amu.

\(E = \Delta m \times \text{(Energy equivalent of 1 amu)}\)

\(E = 0.18466 \text{ amu} \times 931.494 \text{ MeV/amu}\)

Now, let's calculate the value:

\(E \approx 172.0102 \text{ MeV}\)

Rounding to one decimal place, we get approximately 172.0 MeV.

Summary of Calculation

Quantity Value (amu)
Mass of reactants 236.05257
Mass of products 235.86791
Mass Defect (\(\Delta m\)) 0.18466

Energy Released = \(\Delta m \times 931.494 \text{ MeV/amu}\)

Energy Released = 0.18466 \(\times\) 931.494 MeV \(\approx\) 172.0 MeV

This calculated energy matches one of the given options.

Was this answer helpful?

Important Questions from Nuclear Chemistry

  1. For the following nuclear decay series segment,

    \(_{90}^{234}{Th}\) → → → \(_{90}^{230}{Th}\)

    the overall emitted particles are

  2. α particle is charged ___  

  3. Which of the following is used for the production of Nuclear energy?  

  4. Which one of the following reactions is the main cause of the energy radiation from the sun

  5. Tritium is an isotope of hydrogen which is radioactive. It decays by _____________.

Need Expert Advice?

Start Your Preparation with Prepp Mobile App

Download the app from Google Play & App Store
Download the app from Google Play & App Store
Prepp Mobile App