Please select a subject first
Advertisements
Advertisements
Which of the following statements are correct. Answer on the basis of Figure.
(i) The two birdged hydrogen atoms and the two boron atoms lie in one plane;
(ii) Out of six B – H bonds two bonds can be described in terms of 3 centre 2-electron bonds.
(iii) Out of six B – H bonds four B – H bonds can be described in terms of 3 centre 2 electron bonds;
(iv) The four-terminal B – H bonds are two centre-two electron regular bonds.
Concept: undefined >> undefined
Explain why the following compounds behave as Lewis acids?
BCl3
Concept: undefined >> undefined
Advertisements
Explain why the following compounds behave as Lewis acids?
AlCl3
Concept: undefined >> undefined
When BCl3 is treated with water, it hydrolyses and forms [B[OH]4]– only whereas AlCl3 in acidified aqueous solution forms [Al(H2O)6]3+ ion. Explain what is the hybridisation of boron and aluminium in these species?
Concept: undefined >> undefined
Aluminium dissolves in mineral acids and aqueous alkalies and thus shows amphoteric character. A piece of aluminium foil is treated with dilute hydrochloric acid or dilute sodium hydroxide solution in a test tube and on bringing a burning matchstick near the mouth of the test tube, a pop sound indicates the evolution of hydrogen gas. The same activity when performed with concentrated nitric acid, reaction doesn’t proceed. Explain the reason.
Concept: undefined >> undefined
Explain the following:
Boron does not exist as B3+ ion.
Concept: undefined >> undefined
Explain the following:
PbX2 is more stable than PbX4.
Concept: undefined >> undefined
Explain the following:
Pb4+ acts as an oxidising agent but Sn2+ acts as a reducing agent.
Concept: undefined >> undefined
Explain the following:
Electron gain enthalpy of chlorine is more negative as compared to fluorine.
Concept: undefined >> undefined
Explain the following:
Tl (NO3)3 acts as an oxidising agent.
Concept: undefined >> undefined
Identify the compounds A, X and Z in the following reactions:
\[\ce{A + 2HCl + 5H2O -> 2NaCl + X}\]
Concept: undefined >> undefined
Identify the compounds A, X and Z in the following reactions:
\[\ce{X ->[Δ][370 K] HBO2 ->[Δ][> 370 K] Z}\]
Concept: undefined >> undefined
Complete the following chemical equations:
\[\ce{Z + 3 LiAlH4 -> X + 3LiF + 3AlF_3}\]
\[\ce{X + 6H2 -> Y + 6H2}\]
\[\ce{3X + 3O2 ->[Δ] B2O3 + 3H2O}\]
Concept: undefined >> undefined
Match the species given in Column I with the properties mentioned in Column II.
| Column I | Column II |
| (i) \[\ce{BF^{-}4}\] | (a) Oxidation state of central atom is +4 |
| (ii) AICI3 | (b) Strong oxidising agent |
| (iii) SnO | (c) Lewis acid |
| (iv) PbO2 | (d) Can be further oxidised |
| (e) Tetrahedral shape |
Concept: undefined >> undefined
Match the species given in Column I with properties given in Column II.
| Column I | Column II |
| (i) Diborane | (a) Used as a flux for soldering metals |
| (ii) Galluim | (b) Crystalline form of silica |
| (iii) Borax | (c) Banana bonds |
| (iv) Aluminosilicate | (d) Low melting, high boiling, useful for measuring high temperatures |
| (v) Quartz | (e) Used as catalyst in petrochemical industries |
Concept: undefined >> undefined
Match the species given in Column I with the hybridisation given in Column II.
| Column I | Column II |
| (i) Boron in [B(OH)4]– | (a) sp2 |
| (ii) Aluminium in [Al(H2O)6]3+ | (b) sp3 |
| (iii) Boron in B2H6 | (c) sp3d2 |
| (iv) Carbon in Buckminsterfullerene | |
| (v) Silicon in \[\ce{SiO^{4-}4}\] | |
| (vi) Germanium in [GeCl6]2– |
Concept: undefined >> undefined
Describe the general trends in the following properties of the elements in Groups 13 and 14.
Atomic size
Concept: undefined >> undefined
Describe the general trends in the following properties of the elements in Groups 13 and 14.
Ionisation enthalpy
Concept: undefined >> undefined
Describe the general trends in the following properties of the elements in Groups 13 and 14.
Metallic character
Concept: undefined >> undefined
Describe the general trends in the following properties of the elements in Groups 13 and 14.
Oxidation states
Concept: undefined >> undefined
