Yellow phosphorus is kept in

• water

• kerosene

• ether

• alcohol

The decreasing nucleophilicity of the following is:

I. CH₃S^-              II. CH₃O^-

III. ^-OH               IV. EtO^-

• II > III > 1V > I

• III > IV > I > II

• IV > III > I > II

• II < I < IV < III

Which will have maximum ionization energy?

• Na

• Mg

• K

• Bi

Lowest MP and BP is of

• Ar

• Xe

• He

• Ne

When H₂S gas is passed in a metal sulphate solution in presence of NH₄OH, a white precipitate is produced. The metal is identified as

• Zn

• Fe

• Pb

• Hg

Which of the following electronic configuration represents noble gas?

• ns²np⁶

• ns²np⁵

• ns²np⁴

• ns²np³

The correct order of ionisation energy of C, N, O, F is :

• F < 0 < N < C

• F < N < C < 0

• C < N < 0 < F

• C < 0 < N < F

Best reagent for the conversion of AgNO₃ to Ag is

• HClO₄

• H₃PO₂

• HIO₄

• I₂

For the process ,

X (g) + e^- $\to$ X^- (g) ; $\mathrm{\Delta }$H = x

and X^- (g) $\to$ X (g) + e^- ; $\mathrm{\Delta }$H = y

select correct alternate

• Ionisation energy of x^- (g) is y

• Electron affinity of X (g) is x

• Electron affinity of X (g) is - y

• All of the above

270.

Which of the following reactions does not take place?

BF₃ + F^- $\to$B${\mathrm{F}}_4^{-}$          ...(I)

BF₃ + 3F^- $\to$B${\mathrm{F}}_6^{3-}$       ...(II)

AlF₃ + 3F^- $\to$ Al${\mathrm{F}}_6^{3-}$    ...(III)

• Only (I)

• Only (II)

• Only (III)

• Only (I) and (III)