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Question
Identify the compounds A, X and Z in the following reactions:
\[\ce{A + 2HCl + 5H2O -> 2NaCl + X}\]
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Solution
\[\ce{\underset{\underset{(Borax)}{(A)}}{Na2B4O7} + 2HCl + 5H2O -> 2NaCl + \underset{\underset{(Boric acid)}{(X)}}{4H3BO3}}\]
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RELATED QUESTIONS
If B–Cl bond has a dipole moment, explain why BCl3 molecule has zero dipole moment.
Suggest reasons why the B–F bond lengths in BF3 (130 pm) and `"BF"_4^(-)` (143 pm) differ.
What happens when BF3 is reacted with ammonia?
A compound X, of boron reacts with NH3 on heating to give another compound Y which is called inorganic benzene. The compound X can be prepared by treating BF3 with Lithium aluminium hydride. The compounds X and Y are represented by the formulas.
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;
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Explain the following:
Pb4+ acts as an oxidising agent but Sn2+ acts as a reducing agent.
Explain the following:
Electron gain enthalpy of chlorine is more negative as compared to fluorine.
Complete the following chemical equations:
\[\ce{Z + 3 LiAlH4 -> X + 3LiF + 3AlF_3}\]
\[\ce{X + 6H2 -> Y + 6H2}\]
\[\ce{3X + 3O2 ->[Δ] B2O3 + 3H2O}\]
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 |
Describe the general trends in the following properties of the elements in Groups 13 and 14.
Atomic size
Describe the general trends in the following properties of the elements in Groups 13 and 14.
Metallic character
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Though fluorine is more electronegative than chlorine yet BF3 is a weaker Lewis acid than BCl3
Account for the following observations:
PbO2 is a stronger oxidising agent than SnO2
Three pairs of compounds are given below. Identify that compound in each of the pairs which has group 13 element in more stable oxidation state. Give reason for your choice. State the nature of bonding also.
TlCl3, TlCl
A nonmetallic element of group 13, used in making bullet proof vests is extremely hard solid of black colour. It can exist in many allotropic forms and has unusually high melting point. Its trifluoride acts as Lewis acid towards ammonia. The element exihibits maximum covalency of four. Identify the element and write the reaction of its trifluoride with ammonia. Explain why does the trifluoride act as a Lewis acid.
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