Find the energy required to excite `1.10L` 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)`.Also calculate the minimum frequency of a photon to break this bond

Find the energy required to excite `1.10L` od hydrogen gas at `1.0` nm

1.	Find the energy required to excite `1.10L` 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)`.Also calculate the minimum frequency of a photon to break this bond
Answer» Let as first the number of moles of hydrogen atom `n_(H_2) = (PV)/(KT) = (1 xx 1.10)/(0.0921 xx 298) = 0.045` Thus the energy required to break `0.045` and of `H_(2)(H-H) "bond")` is `0.045 xx 436 = 19.62 kJ` Now calculate the energy needed excite the H atom in the first excited sstate i.e. to `n = 2` `Delta E = 2.18 xx 10^(--18) xx Z^(2)((1)/(n_(1)^(2)) - (1)/(n_(2)^(2))) J "atom"^(-1)` `Delta E = 2.18 xx 10^(-18) xx (1)^(2)((1)/(1^(2)) - (1)/(2^(2))) J "atom"^(-1)` `= 1.635 xx 10^(-18) J "atom"^(-1)` Number of H atom of `H_(2)` molecules)`xx 2 = (0.05 xx 6.02 xx 10^(23)) xx 2= 6.02 xx 10^(22)` The energy required to excite the given number of H atom is `6.02 xx 10^(22) xx 1.635 xx 10^(-18) J = 98.43 kJ` So, the total energy required is `19.62 + 98.43 = 118.05 kJ` Now energy required to break a single H-H bond is `(436 xx 10^(3))/(6.023 xx 10^(22)) = 7.238 xx 10^(-19)` = Energy supplied by the photon `rArr 7.238 xx 10^(-19) = hv = 6.026 xx 10^(-34)(v)` `:. v = (7.38 xx 10^(-19))/(6.626 xx 10^(-34))` `rArr v = 1.09 xx 10^(15) Hz`

Discussion

No Comment Found

Related InterviewSolutions

The ratio between the neutrons present in nitrogen atom and silicon atoms with number 14 and 28 is :A. `7:3`B. `3:7`C. `1:2`D. `2:1`
Which one of the following sets of ions represents the collection of isoelectronic species?A. `Na^(+),Mg^(2+),Al^(3+),Cl^(-)`B. `Na^(+),Ca^(2+),Sc^(3+),F^(-)`C. `K^(+),Cl^(-),Mg^(2+),Sc^(3+)`D. `K^(+),Ca^(2+),Sc^(3+),Cl^(-)`
If `I_(0)` is the threshold wavelength for photoelectric emission, 1 the wavelength of light falling on the surface of a metal and m is the mass of the electron, then the velocity of ejected electron is given byA. `[(2h)/(m)(lambda - lambda)]^(1//2)`B. `[(2hc)/(m)(lambda_(0)-lambda)]^(1//2)`C. `[(2hc)/(m){(lambda_(0)-lambda)/(lambda lambda_(0))}]^(1//2)`D. `[(2hc)/(m){(1)(lambda_(0))-(1)/(lambda)}]^(1//2)`
If the threshold wavelength `(lambda_(0))` for spection of electron from metal is `350nm `then work function for the photoelectric emission isA. `1.2 xx 10^(-18) J`B. `1.2 xx 10^(-20) J`C. `6 xx 10^(-29) J`D. `6 xx 10^(-12) J`
Which one of the following sets of ions represents a colloection of isoelectronic species ?A. ` K^+ , Cl^- , Ca^(2+) , Sc^(3+)`B. ` K^+ , Cl^- , Ca^(2+) , Sc^(2+), Sc^(3+)`C. `N^(3-), O^(2-) F^- , S^(2-)`D. `Li^+ , Na^+ , Mg^(2+) , ca^(2+)`.
If `lambda_(0)` is the threshold wavelength for photoelectric emission. `lambda` wavelength of light falling on the surface on the surface of metal, and `m` mass of electron. Then de Broglie wavelength of emitted electron is :-A. `[(h(lambdalambda_(0)))/(2mc(lambda_(0)-lambda))]overset(1)(2)`B. `[(h(lambda_(0)-lambda))/(2mclambdalambda_(0))]overset(1)(2)`C. `[(h(lambda-lambda_(0)))/(2mclambdalambda_(0))]overset(1)(2)`D. `[(hlambdalambda_(0))/(2mc)]overset(1)(2)`
If the threshold wavelength `(lambda_(0))` for ejection of electron from metal is `350 nm ` then work function for the photoelectric emission isA. `1.2 xx 10^-18 J`B. `1.2 xx 10^-20 J`C. `6 xx 10^-19 J`D. `6 xx 10^-12 J`
Elements up to atomic number `103` have been synthesized and studied. If a newly discovered element is found to have an atomic number `106`, its electronic configuration will beA. `[Rn]5 f^14 , 6d^4, 7s^2`B. `[Rn]5 f^14 , 6d^1, 7s^2 7p^3`C. `[Rn]5 f^14 , 6d^6, 7s^0`D. `[Rn]5 f^14 , 6d^5, 7s^1`
The kinetic energy of an electron in the second Bohr orbit of a hydrogen atom is [`a_0` is Bohr radius] :A. `(h^(2))/(4 pi^(2) ma_(0)^(2))`B. `(h^(2))/(16 pi^(2) ma_(0)^(2))`C. `(h^(2))/(32 pi^(2) ma_(0)^(2))`D. `(h^(2))/(64 pi^(2) ma_(0)^(2))`
The kinetic energy of an electron in the second Bohr orbit of a hydrogen atom is [`a_0` is Bohr radius] :A. `h^2/(4pi^2 ma_0^2)`B. `h^2/(16pi^2 ma_0^2)`C. `h^2/(32pi^2 ma_0^2)`D. `h^2/(64pi^2 ma_0^2)`

Find the energy required to excite `1.10L` 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)`.Also calculate the minimum frequency of a photon to break this bond

Discussion

No Comment Found

Related InterviewSolutions

Reply to Comment