Which one of the following group 16 elements does not exist in -2 oxidation state?

• S

• Se

• O

• Po

In which one of the following compounds of xenon, highest number of lone pair of electrons is present in xenon?

• XeF₆

• XeF₄

• XeF₂

• XeOF₃

Which one of the following has the maximum number of P-OH bonds?

• H₃PO₂

• H₃PO₄

• H₄P₂O₆

• H₄P₂O₅

Which one of the following statements is not true in respect of propeties of interhalogen compounds?

• They are all covalent compounds

• They are volatile solids or liquids except ClF

• IF₅ has square pyramidal structure

• They are all paramagnetic in nature

Which of the following noble gases has the nighest positive electron gain enthalpy value?

• Helium

• Krypton

• Argon

• Neon

Oxyacids of phosphorus and the starting materials for their preparation are given below.

Oxyacid	Materials for preparation
A. H3PO2	i. Red P + alkali
B. H3PO3	ii. P4O10 + H2O
C. H3PO4	iii. P2O3 + H2O
D. H4P2O6	iv. White P + alkali

Choose the correct answer from the codes given below

• A - iv; B - iii; C - ii; D - i

• A - i; B - iii; C - ii; D - iv

• A - iv; B - iii; C - i; D - ii

• A - ii; B - iii; C - i; D - iv

Which halide of magnesium has highest ionic character?

• Chloride

• Bromide

• Iodide

• Fluoride

The reaction takes place in two steps as

$$\begin{gathered} \left(\mathrm{i}\right) {\mathrm{NO}}_2\mathrm{Cl}\left(\mathrm{g}\right) \stackrel{{\mathrm{k}}_1}{\to } {\mathrm{NO}}_2\left(\mathrm{g}\right) + \mathrm{Cl}\left(\mathrm{g}\right) \\ \left(\mathrm{ii}\right) {\mathrm{NO}}_2\mathrm{Cl}\left(\mathrm{g}\right) +\mathrm{Cl}\left(\mathrm{g}\right) \stackrel{{\mathrm{k}}_2}{\to } {\mathrm{NO}}_2\left(\mathrm{g}\right) + \mathrm{Cl}\left(\mathrm{g}\right) \end{gathered}$$

Identify the reaction intermediate.

• NO₂Cl (g)

• NO₂(g)

• Cl₂(g)

• Cl(g)

289.

What is the highest oxidation state exhibited by group 17 elements?

• +1

• +3

• +5

• +7

Brown ring test is used for detection of which radical?

• Ferrous

• Nitrite

• Nitrate

• Ferric