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Lakhmir Singh

Identify the incorrect statement.
(1) The transition metals and their compounds are known for their catalytic activity due to their ability to adopt multiple oxidation states and to form complexes.
(2) Interstitial compounds are those that are formed when small atoms like H , C or N are trapped inside the crystal lattices of metals.
(3) The oxidation states of chromium in CrO _{4}^{2-} and Cr _{2} O _{7}^{2-} are not the same.
(4) Cr ^{2+}\left( d ^{4}\right) is a stronger reducing agent than Fe ^{2+}\left( d ^{6}\right) in water.

Correct option (3) Explanation: Interstitial compounds are those formed when small atoms such as H, B, C, or N are trapped inside metal crystal lattices. Fact: On the basis of standard reduction...

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When a ray of light is incident normally on one refracting surface of an equilateral prism of refractive index 1.5, the emerging ray \left[\sin ^{-1}\left(\frac{1}{1.5}\right)=41.8^{\circ}\right]
A) just grazes the second refracting surface.
B) is deviated by 20^{\circ}.
C) is deviated by 30^{\circ}.
D) undergoes total internal reflection at second refracting surface.

Correct answer is D. Critical angle for the material of prism $C=\sin ^{-1}\left(\frac{1}{\mu}\right)$ $=\sin ^{-1}=42^{\circ}$ since angle of incidence at surface $A B\left(60^{\circ}\right)$ is...

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Molarity is defined as A) the number of moles of solute dissolved in one dm3 of the solution B) the number of moles of solute dissolved in 1 kg of solvent C) the number of moles of solute dissolved in 1 dm3 of the solvent D) the number of moles of solute dissolved in 100 ml of the solvent

Correct option is (A) The number of moles of solute dissolved in 1dm3 of the solution is called molarity. Molarity = (moles of solute dissoved) / (volume of solvent in dm3) So, answer is...

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The mass and radius of earth is \mathrm{M}_{\mathrm{c}}, and \mathrm{R}_{\mathrm{c}}, respectively and that of moon is \mathrm{M}_{\mathrm{m}} and \mathrm{R}_{\mathrm{m}} respectively. The distance between the centre of earth and that of moon is ‘D’ . The minimum speed required for a body (mass ‘m’) to project from a point midway between their centres to escape to infinity is
A. \left(\frac{G D}{M_{e}}\right)^{1 / 2}
B. \sqrt{\frac{\left(M_{e}+M_{m}\right)}{D}}
C. 2 \sqrt{G\left(M_{e}+M_{m}\right) / D}
D. \frac{G\left(M_{e}+M_{m}\right)}{2 D}

Correct answer is C. From conservation of energy, since the velocity will be o at infinity, $\frac{1}{2} \mathrm{mv}^{2}-\frac{\mathrm{GmM}_{e}}{\mathrm{~d} / 2}-\frac{\mathrm{GmM}_{d}}{\mathrm{~d}...

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