Q.

The energy released when 717.13kg of Li37 is converted into He24 by proton bombardment is α×1032 eV. The value of α is ______. (Nearest integer)

(Mass of Li37=7.0183 u, mass of He24=4.004 u, mass of proton = 1.008 u and 1 u = 931 MeV/c2 and Avogadro number =6.0×1023)          [2026]
 


Ans.

(6)

L37i+H11⇌2(H24e)+Q

Mass of Reactants:

MLi+Mp=7.0183 u+1.008=8.0263 u

Mass of Product:  2×MHe=2×4.004 u=8.008 u

Mass defect (Δm)=8.0263 u-8.008 u=0.0183 u

Energy (Q)=Δmc2=0.0183×931 MeV≈17.0373 MeV

Number of Li atoms:  N=MassMolar mass×NA

N=717.13kg7×10-3 kg/mol×6.02×1023=617.13×1026

Etotal=N×Q

Etotal=17.0373×117.13×6×1026×106 eV

Etotal≈6×1032 eV

Comparing we get α=6