# Calculate Q-Value of the A Hypothetical reaction

2 1H1 + 2 0n1 —–>2He4

Check whether the reaction is exoergic or endoergic?
The exact mass of 1H1 isotope = 1.0081 a.m.u. and that of 0n1 = 1.0086 a.m.u.
The exact mass of 2He4 = 4.0039 a.m.u.
Where, a.m.u. is Atomic Mass Unit.

The value of Q can be calculated from the masses of the products and reactants of the equation.

(Given) The exact mass of 1H1 isotope = 1.0081 a.m.u. and that of 0n1 = 1.0086 a.m.u.

The exact mass of 2He4 = 4.0039 a.m.u.
Where, a.m.u. is Atomic Mass Unit.

Hence
Sum of the masses of reactants = 2 X 1.0081 + 2 X 1.0086 = 2.0162a.m.u. + 2.0172a.m.u. = 4.0334a.m.u.
Sum of the masses of products = 4.0039 a.m.u.
Therefore, ΔM = Sum of the masses of products – Sum of the masses of reactants
= 4.0039 – 4.0334= – 0.0295a.m.u.

As there is decrease of mass,hence energy is being released.
The value of Q will be therefore Positive i.e.
Q = 0.0295a.m.u.X 931.5 MeV/a.m.u = + 27.47925 MeV
Hence the above reaction is exoergic.