In which one of the pairs of ion given, there is an ion that forms a co-ordination compound with
both aqueous sodium hydroxide and ammonia and an other ion that forms a co-ordination
compound only with aqueous sodium hydroxide?

Ion forms a coordination compound with both aqueous sodium hydroxide and ammonia and other ions forms
coordination compound only with aqueous sodium hydroxide. Zinc forms \( \mathrm{Na}_{2}\left[\mathrm{Zn}(\mathrm{OH})_{4}\right] \) coordination compound with
\( \mathrm{NaOH} \)
\( Z n+2 N a O H(a q) \rightarrow N a_{2}\left[Z n(O H)_{4}\right] \)
Zinc forms a colorless tetraammine with the formula
\( \left[Z n\left(N H_{3}\right)_{4}\right]^{2+} \) \( Z n+4 N H_{3}(a q) \rightarrow\left[Z n\left(N H_{3}\right)_{4}\right]^{2+} \)
Aluminum forms complex with only aqueous sodium hydroxide \( \mathrm{N} a_{3}\left[\mathrm{Al}(\mathrm{OH})_{6}\right] \) and not with ammonia.
\( A l+3 N a O H(a q) \rightarrow N a_{3}\left[A l(O H)_{6}\right] \)
and \( \mathrm{Al}+\mathrm{NH}_{3}(a q) \rightarrow \) no reaction