Question

How much energy is released when $2mole$ of $U^{235}$ is fissioned :

• A. ${10}^{24}MeV$
• B. $24\times {10}^{25}MeV$
• C. ${10}^{24}J$
• D. ${10}^{24}kWh$

Answer 1

The correct option is B $24\times {10}^{25}MeV$

Given,

$n=2mole$

$A=235$

$N_A=6.023\times {10}^{23}atom$

As we know that $mole=\frac{weight}{mass}$

$weight=mole\times mass=n\times A=2\times 235=470g$

No. of atom in 1g of $U^{235}=\frac{N_A}{235}$

No. of atom is 470 g of $U^{235}=\frac{470\times N_A}{235}=2N_A$

Free energy, $E=2N_A\times 200MeV$

$E=2\times 6.023\times {10}^{23}\times 200=24\times {10}^{25}MeV$

The correct option is B.