NEET UG 2017 — Chemistry Physical Chemistry

2017mcqhard

Which one of the following statements is wrong?

Official previous-year question

Held on 30 Apr 2017 · Verified 9 Jul 2026.

Options

A
de-Broglie's wavelength is given by $\lambda =\frac{h}{\mathrm{mv}}$ , were $m=$ mass of the particle, $v=$ group velocity of the particle.
B
The uncertainty principle is $\Delta E\times \Delta t\geq \frac{h}{4\pi }$ .
C
Half-filled and fully-filled orbitals have greater stability due to the greater exchange energy, greater symmetry and more balanced arrangement.
D
The energy of $2s$ orbital is less than the energy of $2p$ orbital in case of hydrogen-like atoms.

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Solution

(i) $\lambda =\frac{h}{p}=\frac{h}{\mathrm{mv}}$

(ii) $\Delta x.\Delta p=\frac{h}{4\pi }$

$\Delta x\times \frac{\Delta p\times \mathrm{dt}}{\Delta t}\geq \frac{h}{4\pi }$ $\therefore \frac{\Delta p}{\Delta t}=f$

$f\Delta x \Delta t\geq \frac{h}{4\pi }$ , $f\Delta x=\Delta E$

$\Delta E.\Delta t\geq \frac{h}{4\pi }$

(iii) ${3}^{\mathrm{rd}}$ statement is true.

(iv) The energy of $2s-$ orbital and $2p-$ orbital in case of hydrogen like atoms is equal because they are single electron species.

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Options

de-Broglie's wavelength is given by $\lambda =\frac{h}{\mathrm{mv}}$ , were $m=$ mass of the particle, $v=$ group velocity of the particle.

The uncertainty principle is $\Delta E\times \Delta t\geq \frac{h}{4\pi }$ .

Half-filled and fully-filled orbitals have greater stability due to the greater exchange energy, greater symmetry and more balanced arrangement.

The energy of $2s$ orbital is less than the energy of $2p$ orbital in case of hydrogen-like atoms.

Solution

(i) $\lambda =\frac{h}{p}=\frac{h}{\mathrm{mv}}$

(ii) $\Delta x.\Delta p=\frac{h}{4\pi }$

$\Delta x\times \frac{\Delta p\times \mathrm{dt}}{\Delta t}\geq \frac{h}{4\pi }$ $\therefore \frac{\Delta p}{\Delta t}=f$

$f\Delta x \Delta t\geq \frac{h}{4\pi }$ , $f\Delta x=\Delta E$

$\Delta E.\Delta t\geq \frac{h}{4\pi }$

(iii) ${3}^{\mathrm{rd}}$ statement is true.

(iv) The energy of $2s-$ orbital and $2p-$ orbital in case of hydrogen like atoms is equal because they are single electron species.

NEET UG 2017 — Chemistry Physical Chemistry

Options

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Solution

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NEET UG 2017 — Chemistry Physical Chemistry

Options

Did you get this right?

Solution

Your note

NEET UG Physical Chemistry in other years

More NEET UG Physical Chemistry questions

Other Chemistry topics for NEET UG

Organic Chemistry

Inorganic Chemistry

Keep practicing Physical Chemistry