The bond order in O${}_2^{-}$ ion is

• 2

• 1

• 2.5

• 1.5

12.

The rms velocity of an ideal gas at constant pressure varies with density (d) as

• $\frac{1}{\sqrt{\mathrm{d}}}$

• d

• $\sqrt{\mathrm{d}}$

• d²

For which reaction change of entropy will be positive?

• H₂(g) + I₂(g) $\rightleftharpoons$ 2HI (g)

• HCl (g) + NH₃ (g) $\rightleftharpoons$ NH₄Cl (s)

• NH₄NO₃ (s) $\rightleftharpoons$ N₂O (g) + 2H₂O (g)

• MgO(s) + H₂(g) $\rightleftharpoons$ Mg(s) + H₂O(l)

The product p of the nuclear reaction

${}_{92}{}^{235}\mathrm{U} + {}_0{}^1\mathrm{n} \to \mathrm{p} + {}_{36}{}^{92}\mathrm{Kr} + 3{}_0{}^1\mathrm{n}$, is

• ${}_{56}{}^{141}\mathrm{Sr}$

• ${}_{56}{}^{141}\mathrm{La}$

• ${}_{56}{}^{141}\mathrm{Ba}$

• ${}_{56}{}^{141}\mathrm{Cs}$

Which of the following acids has the smallest dissociation constant?

• CH₃CHFCOOH

• FCH₂CH₂COOH

• BrCH₂CH₂COOH

• CH₃CHBrCOOH

Which one of the following processes is used for the manufacture of calcium?

• Reduction of CaO with carbon

• Reduction of CaO with hydrogen

• Electrolysis of a mixture of anhydrous CaCl₂ and KCl

• Electrolysis of molten Ca(OH)₂

Fe(OH)₃ can be separated from Al(OH)₃ by the addition of

• NaCl solution

• dil. HCl solution

• NaOH solution

• NH₄Cl and NH₄OH

Select the incorrect statement among the following:

• O₃ is used as germicide for purification of air

• In O₃, O-O bond length is identical with that of molecular oxygen

• O₃ molecule is angular in shape.

• O₃ is an oxidising agent

The brown complex obtained in the detection of nitrate radical is formulated as [Fe(H₂O)₅NO]SO₄. What is the oxidation number of Fe in this complex?

• +1

• +2

• +3

• 0

1 mole of methyl amine on reaction with nitrous acid gives at NTP

• 1.0 L of nitrogen

• 22.4 L of nitrogen

• 11.2 L of nitrogen

• 5.6 L of nitrogen