JEE MainChemistryModeratePhysical Chemistry

The wavelength of a moving body of mass 0.1 mg is 3.31 × 10-29
m. The kinetic energy of the body in J would be

Show answer and solution

\lambda = \frac{h}{mv}

mv = \frac{h}{\lambda}

m^{2}v^{2} = \frac{h^{2}}{m\lambda^{2}}

\frac{1}{2}{mv}^{2} = \frac{h^{2}}{2m\lambda^{2}}

KE = \frac{h^{2}}{2m\lambda^{2}} = \frac{\left( 6.6 \times 10^{- 34} \right)^{2}}{2 \times 10^{- 4} \times \left( 3.31 \times 10^{- 29} \right)^{2}} = 2 \times 10^{- 6}

Source: Grass-G / CH-22 Chemistry Paper 19 Dec. Eng.docx

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