# Homework Help: Energy Released by fission

1. May 21, 2013

### kingstar

1. The problem statement, all variables and given/known data

Estimate the energy released, in Joules, by the fission of 1g of U-235 according to the equation:

$^{235}_{92}{U}$ + $^{1}_{0}{n}$ → $^{144}_{56}{Ba}$ + $^{90}_{36}{Kr}$ + 2$^{1}_{0}{n}$ + Q

atomic masses:

$^{235}_{92}{U}$ = 235.04438u

$^{144}_{56}{Ba}$ = 143.92279u

$^{90}_{36}{Kr}$ = 89.92089u

$^{1}_{0}{n}$ = 1.00866u

Avogadro's number = 6.023 x 1023
1u = 931MeV
1MeV = 1.6 x 10-13J

2. Relevant equations

3. The attempt at a solution

(235.04438u + 1.00866u) - (143.92279u + 89.92089u + 1.00866u + 1.00866u) = 0.19204u

0.19204u x 931 = 178.78924MeV
178.78924 x 1.6 x 10-13J = 2.86 x 10-11

Do I then do (6.023 x 1023/235) x 2.86 x 10-11 = 7.33 x 1010J

For the final answer?

Thanks

2. May 21, 2013

### barryj

Looks good to me.

3. May 21, 2013

### kingstar

Thanks.

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