Ammonia forms the complex ion [Cu(NH3)4]2+ion with copper ions in alka...
The correct answer is option B
In acidic solutions, ammonia reacts with proton and forms ammonium ion which further cannot act as a ligand. Also, no free ammonia molecules are available for co-ordination. Hence, it does not form a complex with copper ion.
The reaction is as follows:
NH3 + H+ → NH4+
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Ammonia forms the complex ion [Cu(NH3)4]2+ion with copper ions in alka...
Well, it's because Ammonia being a Lewis base will react with the acidic medium to form a salt instead
Ammonia forms the complex ion [Cu(NH3)4]2+ion with copper ions in alka...
The reason for the formation of the complex ion [Cu(NH3)4]2+ in alkaline solutions but not in acidic solutions is due to the difference in pH.
In alkaline solutions, the concentration of hydroxide ions (OH-) is high. The presence of hydroxide ions can deprotonate the ammonia (NH3) molecules, forming ammonium ions (NH4+). The ammonium ions can then coordinate with the copper ions (Cu2+), forming the complex ion [Cu(NH3)4]2+.
On the other hand, in acidic solutions, the concentration of hydrogen ions (H+) is high. The presence of hydrogen ions can protonate the ammonia (NH3) molecules, converting them into ammonium ions (NH4+). The ammonium ions cannot coordinate with the copper ions (Cu2+) to form the complex ion [Cu(NH3)4]2+.
Therefore, the pH of the solution plays a crucial role in determining whether the complex ion [Cu(NH3)4]2+ can form or not.