Find the energy required to excite `1L` od hydrogen gas at `1.0` nm and `298 K` to the first excited state of atomic hydrogen .The energy required for the dissacitation of `H-H` bond is `436 kJ mol^(-1)`

Answer

A, B

Explanation

Moles
`H_(2) = (PV)/(RT) = (1 xx 2)/(0.0821 xx 298) = 0.0817`
Energy required for dissociation is
`436 xx 0.0817 = 35.62 KJ`
Energy required to excite one H atom to first excited state
`(n = 2) = 10.2 xx 1.6 xx 10^(-19) J `
Energy required to excite given sample is
`2 xx 0.0817) xx 6 xx 10^(23) xx (10.2 xx 1.6 xx 10^(-19)) xx 10^(-3) KJ = 160 kJ`
Total energy required `= (35.62 + 160 = 195.62 kJ` Also ` E = hv`
`rArr = (E )/(h) = ((436 xx 10^(3))/(6 xx 10^(23))) (1)/(6.63 xx 10^(-34)) = 1.096 xx 10^(15)Hz`