Electromagnetic radiation of wavelength 242nm is just sufficient to ionise the sodium atom. Calculate the ionisation energy of sodium in $$kJ mol^{–1}$$.

Asked by Pragya Singh | 1 year ago |  97

##### Solution :-

Ionization energy (E) of sodium =

$$\dfrac{N_{A}hc}{\lambda }\\ \\$$

$$\dfrac{(6.023\times 10^{23}\, mol^{-1})}{242\times 10^{-9}m}\\ \\$$

$$\dfrac{(6.626\times 10^{-34})Js(3\times 10^{8})ms^{-1} }{242\times 10^{-9}m}$$

$$=4.947\times 10^{5}\, J\, mol^{-1}\\ \\$$

$$=494.7\times 10^{3}\, J\, mol^{-1}\\ \\$$

$$=494\, kJ\, mol^{-1}$$

Answered by Pragya Singh | 1 year ago

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