Advertisements
Advertisements
Question
Calculate the energy released by 1g of natural uranium assuming 200 MeV is released in each fission event and that the fissionable isotope 235U has an abundance of 0.7% by weight in natural uranium.
Solution
235 g of uranium contains 6.02 × 1023 atoms.
1 g of uranium = `1/235 xx 6.023 xx 10^23` atoms
∴ 0.7 g of uranium = `1/235 xx 6.023 xx 10^23 xx 0.007` atoms
1 atom gives 200 MeV.
∴ Total energy released = `(6.023 xx 10^23 xx 0.007 xx 200 xx 10^6 xx 1.6 xx 10^-19)/235 "J" = 5.74 xx 10^8 "J"`
APPEARS IN
RELATED QUESTIONS
Suppose, we think of fission of a `""_26^56"Fe"` nucleus into two equal fragments `""_13^28"Al"`. Is the fission energetically possible? Argue by working out Q of the process. Given `"m"(""_26^56 "Fe") = 55.93494 "u"` and `"m"(""_13^28 "Al") = 27.98191 "u"`.
The fission properties of `""_94^239"Pu"` are very similar to those of `""_92^235 "U"`. The average energy released per fission is 180 MeV. How much energy, in MeV, is released if all the atoms in 1 kg of pure `""_94^239 "Pu"` undergo fission?
A 1000 MW fission reactor consumes half of its fuel in 5.00 y. How much `""_92^235"U"` did it contain initially? Assume that the reactor operates 80% of the time, that all the energy generated arises from the fission of `""92^235"U"` and that this nuclide is consumed only by the fission process.
Calculate and compare the energy released by a) fusion of 1.0 kg of hydrogen deep within Sun and b) the fission of 1.0 kg of 235U in a fission reactor.
If three helium nuclei combine to form a carbon nucleus, energy is liberated. Why can't helium nuclei combine on their own and minimise the energy?
The mass of a neutral carbon atom in ground state is
As compared to 12C atom, 14C atom has
The heavier nuclei tend to have larger N/Z ratio because
(a) a neutron is heavier than a proton
(b) a neutron is an unstable particle
(c) a neutron does not exert electric repulsion
(d) Coulomb forces have longer range compared to the nuclear forces.
As the mass number A increases, which of the following quantities related to a nucleus do not change?
A free neutron decays to a proton but a free proton does not decay to a neutron. This is because
A uranium reactor develops thermal energy at a rate of 300 MW. Calculate the amount of 235U being consumed every second. Average released per fission is 200 MeV.
Calculate the Q-value of the fusion reaction 4He + 4He = 8Be. Is such a fusion energetically favourable? Atomic mass of 8Be is 8.0053 u and that of 4He is 4.0026 u.
(Use Mass of proton mp = 1.007276 u, Mass of `""_1^1"H"` atom = 1.007825 u, Mass of neutron mn = 1.008665 u, Mass of electron = 0.0005486 u ≈ 511 keV/c2,1 u = 931 MeV/c2.)
Calculate the energy that can be obtained from 1 kg of water through the fusion reaction 2H + 2H → 3H + p. Assume that 1.5 × 10−2% of natural water is heavy water D2O (by number of molecules) and all the deuterium is used for fusion.
(Use Mass of proton mp = 1.007276 u, Mass of `""_1^1"H"` atom = 1.007825 u, Mass of neutron mn = 1.008665 u, Mass of electron = 0.0005486 u ≈ 511 keV/c2,1 u = 931 MeV/c2.)
Which particle is most likely to be captured by a 235u nucleus and cause it to undergo fission?
Assuming that about 200 MeV of energy is released per fission of 92U235 nuclei, then the mass of U235 consumed per day in a fission reactor of power 1 megawatt will be approximately ______.
Distinguish between nuclear fission and fusion giving an example of each.
A heavy nucleus P of mass number 240 and binding energy of 7.6 MeV per nucleon splits into two nuclei Q and R of mass number 110 and 130 and binding energy per nucleon of 8.5 MeV and 8.4 MeV respectively. Calculate the energy released in fission.
