According to Werner's theory, the primary valencies of the central metal atom :

• (A) are satisfied by neutral molecules or negative ions.
• (B) are equal to its coordination number.
• (C) are satisfied by negative ions.
• (D) are non-ionisable.

The oxidation number of Pt in [Pt(en)₂Cl₂]²⁺ is :

• (A) + 3
• (B) + 4
• (C) + 2
• (D) + 6

Which of the following product is formed when salicylic acid is treated with (CH₃CO)₂O in the presence of acid ?

• (A) o-C₆H₄(COOCH₃)(OH) - methyl 2-hydroxybenzoate
• (B) o-C₆H₄(OCOCH₃)(OH)
• (C) o-C₆H₄(COCH₃)(COOH)
• (D) o-C₆H₄(OCOCH₃)(COOH) - aspirin (acetylsalicylic acid)

Which reagent is used to distinguish between primary, secondary and tertiary amines ?

• (A) C₆H₅SO₂Cl
• (B) C₆H₅COCl
• (C) CHCl₃ + ethanolic KOH
• (D) NaOH + I₂

On electrolysis of very dilute aqueous solution of NaCl using platinum electrodes :

• (A) H₂ gas is evolved at anode.
• (B) Na is produced at anode.
• (C) O₂ gas is evolved at anode.
• (D) H₂ gas is evolved at cathode.

The correct order of decreasing basic strength in aqueous solution of the following is :

• (A) (C₂H₅)₃N > C₂H₅NH₂ > (C₂H₅)₂NH
• (B) (C₂H₅)₂NH > C₂H₅NH₂ > (C₂H₅)₃N
• (C) C₂H₅NH₂ > (C₂H₅)₂NH > (C₂H₅)₃N
• (D) (C₂H₅)₂NH > (C₂H₅)₃N > C₂H₅NH₂

The mole fraction of a solute in 2.0 molal aqueous solution is :

• (A) 1.87
• (B) 0.347
• (C) 0.0347
• (D) 0.00347

Which of the following transition metals shows +1 and +2 oxidation states ?

• (A) Mn
• (B) Zn
• (C) Cu
• (D) Sc

On hydrolysis, which of the following carbohydrates gives only β-glucose ?

• (A) Starch
• (B) Sucrose
• (C) Maltose
• (D) Cellulose

Consider the following compounds : Chlorobenzene (I), 2,4,6-trinitrochlorobenzene (II), 2,4-dinitrochlorobenzene (III), 4-nitrochlorobenzene (IV). The correct order of increasing ease of nucleophilic substitution reactions of these compounds is :

• (A) I < IV < III < II
• (B) I < III < IV < II
• (C) II < III < IV < I
• (D) IV < III < II < I