`U^(235) + n^(1)rarr` fission product + neutron + 3.2`xx 10^(-11)j`. The energy released , when 1g of `u^(235)` finally undergoes fission , is
A. `12.75xx10^(8)kj`
B. `18.60xx10^(9)kj`
C. `8.21xx10^(7)kj`
D. `6.55xx10^(6)kj`
Correct Answer - C
235 g of u-235 contains `6.023xx10^(23)` atoms
1g u-235=`(6.023xx10^(23))/(235)atoms`
`therefore` Energy relaeased =`(3.2xx10^(-11)xx6.023xx10^(23))/(235)j`
`=8.21xx10^(10)j`
`8.21xx10^(7) kj`
Correct Answer - (a) `2_(0)^(1)n` , (b) ` ._(36)^(82) Kr`
`._(92)^(235)U+_(0)^(1)nrarr ._(52)^(137)A+_(40)^(97)B+X ._(0)n^(1)`
(as the reaction is balanced with respect to nuclear charge, the missing particle must be neutral i.e. neutron)...
Correct Answer - B
(B) the fission per second `=4xx10^(20)`
So , the energy relased per second
`=4xx10^(20) xx250MeV `
`=4xx10^(20) xx250xx10^(6) xx1.6xx10^(-19) J`
therefore , energy relased in 10 h`=...
Correct Answer - A
(a) Let there is n number of fission per second produces a power of 6.4 W, then
`nxx200x10^(6) xx16x10^(-19) Js^(-1) =6.4Js^(-1)`
`therefore n=(6.4)/( 200xx10^(-13) xx1.6)=(4)/(2xx10^(-11))=2xx10^(11)`
Correct Answer - A
(a) Energy relased in one fission of `""_(92)^(235)U` nucleus `=200 meV `
Mass of uranium = 1 g
we know that , 235 g of ` ""^(235)U`...
Correct Answer - A
Power, `P=(nE)/(t)`
Given, `n=2xx10^(18)` fission per second
E=185MeV
Here, `P=(2xx10^(18)xx185xx10^(6)eV)/(1)`
`implies=2xx10^(18)xx185xx10^(6)xx16xx10^(-19)=59.2MW`
Correct Answer - A
`_(92)U^(256)` nucleus absorbs a neutron and then disntegratein `_(54)Xe^(139),_(38)Sr^(94)` and X.
Thus
`_(92U^(235)+_(0)n^(1)rarr_(54)Xe^(139)+_(38)Sr^(94)+3_(0)n^(1))`
Hence the product is 3 neutrons.
Correct Answer - A
For zero order reaction,
x=kt
`:. (a)/(2)=kxxt_(1//2),i.e.,t_(1//2)=(a)/(2k)" ".....(i)`
For frist order reaction,
`t_(1//2)=(log_(e)2)/(k)" ".....(ii)`
From eqs. (i) and (ii), `(a)/(2k)=(log_(e)2)/(k)`
`a=log_(e)4M`