Hydrogen & s-Block · JEE Main previous year questions

The hydride that is NOT electron deficient :

1. A.${\mathrm{B}}_2{\mathrm{H}}_6$
2. B.$\mathrm{Al}{\mathrm{H}}_3$
3. C.$\mathrm{Ga}{\mathrm{H}}_3$
4. D.$\mathrm{Si}{\mathrm{H}}_4$

Hydrogen peroxide oxidises $[\text{Fe}(\text{CN}{)}_6{]}^{4-}$ to $[\text{Fe}(\text{CN}{)}_6{]}^{3-}$ in acidic medium but reduces $[\text{Fe}(\text{CN}{)}_6{]}^{3-}$ to $[\text{Fe}(\text{CN}{)}_6{]}^{4-}$ in alkaline medium. The other products formed are, respectively :

1. A.${\text{H}}_2\text{O}$ and $({\text{H}}_2\text{O}+{\text{OH}}^{-})$
2. B.$({\text{H}}_2\text{O}+{\text{O}}_2)$ and ${\text{H}}_2\text{O}$
3. C.$({\text{H}}_2\text{O}+{\text{O}}_2)$ and $({\text{H}}_2\text{O}+{\text{OH}}^{-})$
4. D.${\text{H}}_2\text{O}$ and $({\text{H}}_2\text{O}+{\text{O}}_2)$

1. A.
2. B.
3. C.
4. D.

2-chloro-2-methylpentane on reaction with sodium methoxide in methanol yields: (a) ${\mathrm{C}}_2{\mathrm{H}}_5\mathrm{C}{\mathrm{H}}_2-\underset{\mathrm{C}{\mathrm{H}}_3}{\stackrel{\mathrm{C}{\mathrm{H}}_3}{\mathrm{C}}}-\mathrm{OC}{\mathrm{H}}_3$ (b) ${\mathrm{C}}_2{\mathrm{H}}_5\mathrm{C}{\mathrm{H}}_2-\underset{\mathrm{C}{\mathrm{H}}_3}{\mathrm{C}}=\mathrm{C}{\mathrm{H}}_2$ (c) ${\mathrm{C}}_2{\mathrm{H}}_5\mathrm{CH}=\underset{\mathrm{C}{\mathrm{H}}_3}{\mathrm{C}}-\mathrm{C}{\mathrm{H}}_3$

1. A.All of these
2. B.$(a)$ and $(c)$
3. C.$(c)$ only
4. D.$(a)$ and $(b)$

1. A.
2. B.
3. C.
4. D.

The major product obtained on interaction of phenol with sodium hydroxide and carbon dioxide is :

1. A.benzoic acid
2. B.salicylaldehyde
3. C.salicylic acid
4. D.phthalic acid

Phenyl magnesium bromide reacts with methanol to give

1. A.a mixture of anisole and Mg(OH)Br
2. B.a mixture of benzene and Mg(OMe)Br
3. C.a mixture of toluene and Mg(OH)Br
4. D.a mixture of phenol and Mg(Me)Br

The ionic mobility of alkali metal ions in aqueous solution is maximum for :

1. A.${\mathrm{K}}^{+}$
2. B.$\mathrm{R}{\mathrm{b}}^{+}$
3. C.$\mathrm{L}{\mathrm{i}}^{+}$
4. D.$\mathrm{N}{\mathrm{a}}^{+}$

The number and type of bonds between two carbon atoms in calcium carbide are

1. A.One sigma, one pi
2. B.One sigma, two pi
3. C.Two sigma, one pi
4. D.Two sigma, two pi

Beryllium and aluminium exhibit many properties which are similar. But the two elements differ in :

1. A.exhibiting maximum covalency in compounds
2. B.exhibiting amphoteric nature in their oxides
3. C.forming covalent halides
4. D.forming polymeric hydrides

On mixing ethyl acetate with aqueous sodium chloride, the composition of the resultant solution is

1. A.$\mathrm{C}{\mathrm{H}}_3\mathrm{COO}{\mathrm{C}}_2{\mathrm{H}}_5+\mathrm{NaCl}$
2. B.$\mathrm{C}{\mathrm{H}}_3\mathrm{Cl}+{\mathrm{C}}_2{\mathrm{H}}_5\mathrm{COONa}$
3. C.$\mathrm{C}{\mathrm{H}}_3\mathrm{COCl}+{\mathrm{C}}_2{\mathrm{H}}_5\mathrm{OH}+\mathrm{NaOH}$
4. D.$\mathrm{C}{\mathrm{H}}_3\mathrm{COONa}+{\mathrm{C}}_2{\mathrm{H}}_5\mathrm{OH}$

Which of the following undergoes reaction with 50% sodium hydroxide solution to give the corresponding alcohol and acid?

1. A.Phenol
2. B.Benzoic acid
3. C.Butanal
4. D.Benzaldehyde

$\mathrm{K}{\mathrm{O}}_2$ (potassium super oxide) is used in oxygen cylinders in space and submarines because it :

1. A.absorbs $\mathrm{C}{\mathrm{O}}_2$ and increases ${\mathrm{O}}_2$ content
2. B.eliminates moisture
3. C.absorbs $\mathrm{C}{\mathrm{O}}_2$
4. D.produces ozone

The metallic sodium disolves in liquid ammonia to form a deep blue coloured solution. The deep blue colour is due to formation of :

1. A.solvated electron, $\mathrm{e}(\mathrm{N}{\mathrm{H}}_3{)}_{\mathrm{x}}^{-}$
2. B.solvated atomic sodium, $\mathrm{Na}(\mathrm{N}{\mathrm{H}}_3{)}_{\mathrm{y}}$
3. C.$(\mathrm{N}{\mathrm{a}}^{+}+\mathrm{N}{\mathrm{a}}^{-})$
4. D.$\mathrm{NaN}{\mathrm{H}}_2+{\mathrm{H}}_2$