Question

The energy released when 0.375 kg of uranium are converted into energyis equal toa. 2.35 x 1014 Jb. 3.38 x 1016 JC. 4.53 x 1016 Jd. 7.69 x 1016 j

Answer 1

Given that the mass of uranium is m = 0.375 kg = 375 g.

We have to find the energy.

First, we need to find the number of moles.

The number of moles can be calculated as

$\begin{gathered} \text{Number of moles =}\frac{Given\text{ mass}}{atomic\text{ mass}} \\ =\frac{375}{235} \\ =1.59\text{ } \end{gathered}$

Next, we have to convert the number of moles into the number of atoms.

The number of atoms will be

$\begin{gathered} \text{Number of atoms=1.59}\times\text{6.022}\times10^{23} \\ =\text{ 9.57}\times10^{23} \end{gathered}$

One atomic mass unit releases 931.5 MeV energy.

The energy can be calculated as

$\begin{gathered} E=\text{ number of atoms}\times931.5MeV\times atomic\text{ mass of uranium} \\ =9.57\times10^{23}\times(931.5\times10^6eV)\times235 \\ =\text{ }2.095\text{ }\times10^{35}eV\text{ } \\ =\text{ 2.095}\times10^{35}\times1.6\times10^{-19}\text{ J} \\ =\text{ 3.35 }\times10^{16\text{ }}J \end{gathered}$