Roasting of sulphides gives the gas 'X' as a by-product. This is a colourless gas with the choking smell of burnt sulphur and causes great damage to respiratory organs as a result of acid rain. Its aqueous solution is acidic, acts as an oxidising agent, and its acid has never been isolated. The gas 'X' is:

1. SO₂

2. CO₂

3. SO₃

4. H₂S

Which of the following statements is not valid for oxoacids of phosphorus?

1. Orthophosphoric acid is used in the manufacture of triple  superphosphate

2. Hypoposhphorous acid is a diprotic acid

3. All oxoacids contain tetrahedral four coordinated phosphorus

4. All oxoacids contain at least one P=O unit and one P-OH group

Sulphur trioxide can be obtained by which of the following reaction

1. $CaS{O}_4+C\stackrel{∆}{\to }$

2. $F{e}_2(S{O}_4{)}_3\stackrel{∆}{\to }$

3. $S+H_{2}S{O}_4\stackrel{∆}{\to }$

4. $H_{2}S{O}_4+PC{l}_5\stackrel{∆}{\to }$

1.  1 sigma and 2 pi bonds

2.  2 sigma and 2 pi bonds

3.  1 sigma and 1 pi bonds

4.  2 sigma and 1 pi bonds

Which is the correct thermal stability order for ${\mathrm{H}}_2\mathrm{E}\left(\mathrm{E}=\mathrm{O}, \mathrm{S}, \mathrm{Se}, \mathrm{Te} \mathrm{and} \mathrm{Po}\right)?$

1.  ${\mathrm{H}}_2\mathrm{Se}<{\mathrm{H}}_2\mathrm{Te}<{\mathrm{H}}_2\mathrm{Po}<{\mathrm{H}}_2\mathrm{O}<{\mathrm{H}}_2\mathrm{S}$

2.  ${\mathrm{H}}_2\mathrm{S}<{\mathrm{H}}_2\mathrm{O}<{\mathrm{H}}_2\mathrm{Se}<{\mathrm{H}}_2\mathrm{Te}<{\mathrm{H}}_2\mathrm{Po}$

3.  ${\mathrm{H}}_2\mathrm{O}<{\mathrm{H}}_2\mathrm{S}<{\mathrm{H}}_2\mathrm{Se}<{\mathrm{H}}_2\mathrm{Te}<{\mathrm{H}}_2\mathrm{Po}$

4.  ${\mathrm{H}}_2\mathrm{Po}<{\mathrm{H}}_2\mathrm{Te}<{\mathrm{H}}_2\mathrm{Se}<{\mathrm{H}}_2\mathrm{S}<{\mathrm{H}}_2\mathrm{O}$

Match the Xenon compounds in Coloumn-I with its structure in Column-II and assign the correct code:

                    Column-I                      Column-II

(a)              XeF₄                 (i)         pyramidal

(b)              XeF₆                 (ii)        square planar

(c)              XeOF₄               (iii)       distorted octahedral

(d)              XeO₃                 (iv)       square pyramidal

Code:

                (a)       (b)       (c)       (d)

1.             (iii)      (iv)       (i)        (ii)

2.              (i)       (ii)        (iii)      (iv)

3.              (ii)      (iii)       (iv)       (i)

4.              (ii)      (iii)        (i)        (iv)

Match the following:

(a)   Pure nitrogen          (i)      Chlorine

(b)   Haber process         (ii)     Sulphuric acid

(c)   Contact process       (iii)     Ammonia

(d)   Deacon's process     (iv)     Sodium azide or Barium azide

Which of the following is the correct option?

           (a)     (b)     (c)     (d)

1.        (iv)    (iii)     (ii)     (i)

2.         (i)     (ii)      (iii)    (iv)

3.         (ii)     (iv)      (i)    (iii)

4.         (iii)     (iv)     (ii)     (i)

Identify the correct formula of 'oleum' from the following

1. $H_2{S}_2{O}_7$

2. $H_{2}S{O}_3$

3. $H_{2}S{O}_4$

4. $H_2{S}_2{O}_8$

At 25$°$C, nitrogen exists as ${\mathrm{N}}_2$ and phosphorus exists as ${\mathrm{P}}_4$ because

1.  ${\mathrm{N}}_2$ has valence electrons only in bonding and nonbonding orbitals, while P has valence electrons in both bonding and antibonding orbitals

2.  Higher electronegativity of N favors the formation of multiple bonds

3.  The bigger size of P does not favor multiple bonds

4.  P has a preference to adapt structures with small bond angles.

${\mathrm{HClO}}_4$ is a stronger acid than HCIO. The correct statement is

1.  ${\mathrm{ClO}}_4^{-}$ ion is more stabilized than ${\mathrm{ClO}}^{-}$

2.  ${\mathrm{ClO}}_4^{-}$ ion has higher hydration energy than ${\mathrm{ClO}}^{-}$

3.  ${\mathrm{HClO}}_4$ is better solvated in water than HClO

4.  In ${\mathrm{HClO}}_4$, H is attached to Cl, while in HClO it is attached to O