In the reactions (i) nH2O + Cl– → [Cl(H2O)n]– (ii) 6H2O + Mg2+ → [Mg(H2O)6]2+ water acts as :
an acid in (i) and base in (ii)
In the Lewis picture an acid is an electron-pair acceptor and a base is an electron-pair donor. Solvation of ions by water can therefore involve water in either role, depending on which end of the water molecule faces the ion.
In reaction (i) the anion Cl– is hydrated. Its lone pairs are donated towards the slightly positive hydrogen atoms of water, forming O–H···Cl– hydrogen bonds. Water accepts electron density through its O–H σ* orbital, so it behaves as an acid (a hydrogen-bond donor, or Lewis acid) towards chloride.
In reaction (ii) the small, highly charged cation Mg2+ has vacant orbitals. Each of six water molecules donates an oxygen lone pair to the metal to give the aqua complex [Mg(H2O)6]2+, so water behaves as a Lewis base (a ligand).
Thus water is an acid in the chloride hydration and a base in the magnesium hydration. Calling it an acid in both, a base in both, or a base towards chloride and an acid towards Mg2+ reverses at least one of these electron-pair directions.
an acid in (i) and base in (ii) option is correct.
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Important Questions from Mixed Topic (MH-SET)
.................... is a client server application that identifies each host on the internet with a unique user-friendly name.
Every OS has a ................ or .......... which primarily resides in the main memory of the computer to perform some of the basic functions of the OS.
(i) Kernel
(ii) Interface
(iii) Nucleus
(iv) Compiler
Codes:
Which of the following are referred to as low level language?
(i) Machine language
(ii) Assembly language
(iii) High level language
(iv) Natural language
Codes:
Match the following:
List I List II (a) New York Public Library (i) Shelv AR (b) Miami University Augmented Research Group (ii) Smart library (c) Oula University Library (iii) Wolf Walk (d) North Carolina State University (iv) Find the future Codes:
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