In an amino acid, the carboxyl group ionises at p${\mathrm{k}}_{{\mathrm{a}}_1}$ = 2.34 and ammonium, ion at p${\mathrm{k}}_{{\mathrm{a}}_2}$ = 9.6. The isoelectric point of the amino acid is at pH

• 5.97

• 11.94

• 2.34

• 9.60

In the reaction

K₂Cr₂O₇ $\stackrel{∆}{\to }$ K₂CrO₄ + O₂ + (X), (X) is

• CrO₃

• C₂O₇

• Cr₂O₃

• CrO₄

13.

What are the species (A) and (B) in the following

CrO₃ + H₂O → (A) $\stackrel{{\mathrm{OH}}^{-}}{\to }$ (B)

• H₂CrO₄, H₂Cr₂O₇

• H₂Cr₂O₇, Cr₂O₃

• CrO${}_4^{2-}$, Cr₂O${}_7^{2-}$

• H₂CrO₄, CrO${}_4^{2-}$

In the reaction,

2FeCl₃ + H₂S → 2FeCl₂ + 2HCl + S

The correct statement is

• FeCl₃ acts as an oxidising agent

• H₂S and FeCl₃ both act as an oxidising agent

• FeCl₃ get oxidised while H₂S get reduced

• H₂S acts as an oxidising agent

In dilute alkaline solution of MnO${}_4^{-}$ changes to

• MnO${}_4^{2-}$

• MnO₂

• Mn₂O₃

• MnO

Which of the following act as an oxidising agent?

• Np⁴⁺

• Sm²⁺

• Eu²⁺

• Yb²⁺

Transition elements exhibit variable valencies, because they release electrons from the following orbits

• ns

• ns and np

• (n - 1) d and ns

• nd and (n - 1)d

Potassium fluoride has NaCl type structure. What is the distance between K⁺ and F^- ions, if edge length of unit cell is 'a'.

• $\frac{\mathrm{a}}{2}$

• $\frac{\mathrm{a}}{4}$

• 2a

• 4a

The flame colours of metal ions are due to

• Schottky defect

• Frenkel defect

• Metal excess defect

• Metal deficient defect

On passing 3A of electricity for 50 min, 1.8 g metal is deposited, the equivalent mass of metal is

• 9.3

• 19.3

• 38.3

• 39.9