Question

How much energy (J) is contained in 1.1 kg of water if its natural deuterium is used in the fusion reaction of 21H+21H?31H+ 11H?

Compare to the energy obtained from the burning of 1.1 kg of gasoline, about 5.5×10⁷ J .

Answer 1

mass on left = 2 (2.014101778) u

mass on right = 3.016049282 + 1.0078250322 u

mass diff = mass on left - mass on right

= 4.33 x 10^-3 u

Energy released by this reaction = delta(m) c^2

= (4.33 x 10^-3)(1.66 x 10^-27)(3 x 10^8)^2

and number of reaction can happen in 1kg of water

= n NA

= (1.1 / (18 x 1.66 x 10^-27 kg))

Energy obtained = (1.1 / (18 x 1.66 x 10^-27))((4.33 x 10^-3)(1.66 x 10^-27)(3 x 10^8)^2)

= 2.3815 x 10^13 J .....Ans

ratio = (2.3815 x 10^13)/(5.5 x 10^7)

= 4.33 x 10^5 times more