21.

Oxidation number of Cr in K₂Cr₂O₇ is

• 2

• 4

• 6

• 7

Azeotropic mixture of HCl and water has:

• 20.2% HCl

• 22.2% HCl

• 63% HCl

• 84% HCl

The IUPAC name of the following compound is

• 2-ethylpentanol-4

• 3-methylhexanol-3

• 4-methylhexanol-2

• 4-ethylpentanol-2

Quartz is an example of

• cyclic silicate

• chain silicate

• frame work silicate

• sheet silicate

Which of the following is most powerful oxidising agent?

• I₂

• Cl₂

• Br₂

• F₂

Deuterium oxide is used in nuclear reactor as

• source of $\mathrm{\alpha }$-particle

• source of deuteron

• moderator

• fuel

Silicon is an important constituent of

• alloys

• vegetables

• animals

• rocks

Fenton's reagent is

• NaOH + FeSO₄

• H₂O₂ + FeSO₄

• H₂O₂ + ZnSO₄

• H₂O₂ + MgSO₄

Strongest Bronsted base among the following anions is

• Cl${\mathrm{O}}_4^{-}$

• Cl${\mathrm{O}}_3^{-}$

• Cl${\mathrm{O}}_2^{-}$

• ClO^-

Sodium pyrophosphate is represented by which of the following formula?

• Na₂P₂O₄

• Na₄P₂O₅

• Na₄P₂O₇

• Na₂P₂O₅