What is the binding energy of a mole of nuclei with a mass defect of [tex]0.00084 \, \text{kg/mol}[/tex]?

A. [tex]2.52 \times 10^8 \, \text{J/mol}[/tex]

B. [tex]7.56 \times 10^{13} \, \text{J/mol}[/tex]

C. [tex]7.56 \times 10^{16} \, \text{J/mol}[/tex]

D. [tex]2.52 \times 10^5 \, \text{J/mol}[/tex]



Answer :

To determine the binding energy of a mole of nuclei with a given mass defect, we will use Einstein's famous mass-energy equivalence formula:

[tex]\[ E = mc^2 \][/tex]

where:
- [tex]\( E \)[/tex] is the energy,
- [tex]\( m \)[/tex] is the mass,
- [tex]\( c \)[/tex] is the speed of light in a vacuum (approximately [tex]\( 3 \times 10^8 \)[/tex] meters per second).

Given:
- Mass defect, [tex]\( m = 0.00084 \)[/tex] kilograms per mole,
- Speed of light, [tex]\( c = 3 \times 10^8 \)[/tex] meters per second.

Let's compute the binding energy, [tex]\( E \)[/tex]:

[tex]\[ E = mc^2 \][/tex]

Substitute the given values:

[tex]\[ E = (0.00084 \text{ kg/mol}) \times (3 \times 10^8 \text{ m/s})^2 \][/tex]

First, compute the speed of light squared:

[tex]\[ (3 \times 10^8)^2 = 9 \times 10^{16} \text{ (m/s)}^2 \][/tex]

Now, multiply this with the mass defect:

[tex]\[ E = 0.00084 \text{ kg/mol} \times 9 \times 10^{16} \text{ J/kg} \][/tex]

[tex]\[ E = 0.00084 \times 9 \times 10^{16} \text{ J/mol} \][/tex]

[tex]\[ E = 7.56 \times 10^{13} \text{ J/mol} \][/tex]

Therefore, the binding energy of a mole of nuclei with a mass defect of 0.00084 kilograms per mole is:

[tex]\[ \boxed{7.56 \times 10^{13} \text{ J/mol}} \][/tex]

So, the correct answer is:
[tex]\[ \text{B. } 7.56 \times 10^{13} \text{ J/mol} \][/tex]