Aluminium becomes passive in nitric acid because it-

1. Is a noble metal

2. Forms a thin film of oxide

3. Has a positive reduction potential

4.  None of the above

The stability of the +1 oxidation state increases in the sequence:

1. Al <Ga<In<Tl

2. Tl<In<Ga<Al

3. In<Tl<Ga<Al

4. Ga<In<Al<Tl

${}_{}$
\(\mathrm{Al}_2 \mathrm{O}_3\) reacts with-

The correct explanation for the lower atomic radius of Ga as compared to Al is -

1. Poor shielding effect of the 2d-electrons

2. Poor shielding effect of the 3d-electrons

3. Poor shielding effect of the 3p-electrons

4. Poor shielding effect of the 2s-electrons

Borax bead test is responded by:

1.  Divalent metals

2.  Heavy metals

3.  Light metals

4.  Metal which forms coloured metaborates

Match the species given in Column I with the properties mentioned in Column II.

Codes:

The products formed by the oxidation of ${\mathrm{NaBH}}_4$ $\mathrm{and}$ ${\mathrm{l}}_2$ are:

1.  ${\mathrm{B}}_2{\mathrm{H}}_6$ $\mathrm{and}$ $\mathrm{Nal}$ $\mathrm{only}$

2.  ${\mathrm{B}}_2{\mathrm{H}}_6,$ ${\mathrm{H}}_2$ $\mathrm{and}$ $\mathrm{Nal}$ $$

3.  ${\mathrm{Bl}}_3$ $\mathrm{and}$ $\mathrm{NaH}$

4.  ${\mathrm{NaBl}}_4$ $\mathrm{and}$ $\mathrm{Hl}$ $$

AlF₃ is soluble in HF only in the presence of KF due to the formation of:

From the following, the compound(s) that react(s) with \(\mathrm{BF}_3\) is/are -

Aluminium chloride in acidified aqueous solution forms a complex 'A'.
The formula of A and hybridisation state of Al in 'A' is respectively:

1. [Al(H₂O)₆]³⁺, sp³d²

2. [Al(H₂O)₄]³⁺, sp³

3. [Al(H2O)4]3+, dsp2

4. [Al(H₂O)]³⁺, d²sp³