Calculating Binding Energy for Hydrogen Positron Emission

[burg25]

Homework Statement

Find the binding energy for hydrogen in kJ/mol through positron emission.

4(¹₁H) → ⁴₂He + 2(⁰₊₁ß)

Homework Equations

E=Δmc²
Mass of Hydrogen: 1.0079 amu
Mass of Helium: 4.0026 amu
1 amu = 1.6605 x 10^-27kg

The Attempt at a Solution

Here is what I did:

Eb= ((number of protons)xmass hydrogen)-mass of helium)*1.6605x10-27kg/amu)*c^2
Eb = ((4*1.0079 - 4.0026) * 1.6605*10^-27)*(2.998x10⁸)²
Eb= 4.33x10^-12 kg m²/s² = 4.33x10^-12 J
Eb = 4.33 x 10^-15 kJ
Eb = 4.33 x 10^-15 * 6.022 x10²³
Eb = 2.61 x 10⁹ kJ/mol

 

[chemisttree]

Haven't you neglected the mass of the 2 positrons?

In the equation, E=Δmc², the Δm = mass of reactants - mass of all products (including positrons)

 

[burg25]

Isn't a positron basically massless considering it would just have the mass of an electron or will it make a big difference?