Question

What is the end product when \[Sn\] is fused with \[NaOH\] ?

Answer 1

Hint: Here, we are asked to find the end product when \[Sn\] is fused with\[NaOH\] . The symbol ‘ \[Sn\] ’ denotes tin and ‘ \[NaOH\] ’ is sodium hydroxide. When tin is fused with sodium hydroxide, it leads to the formation of colourless salt of an inorganic compound.

Complete answer:
When tin ‘ \[Sn\] ’ reacts with excess sodium hydroxide ‘ \[NaOH\] ’, it leads to the formation sodium stannite \[(N{a_2}Sn{O_2})\] , sodium stannate \[(N{a_2}Sn{O_3})\] and hydrogen gas\[({H_2})\].
The following reaction are involved during the reaction:
\[Sn\, + \,2NaOH \to N{a_2}Sn{O_2}\, + {H_2}\]
\[Sn\, + \,2NaOH\, + {H_2}O \to N{a_2}Sn{O_3}\, + \,2{H_2}\]
The IUPAC name of sodium stannate is Sodium hexahydroxostannate (IV). It is a colourless salt and it forms by dissolving metallic tin or tin (IV) oxide in sodium hydroxide. It is an inorganic compound and has the chemical formula \[N{a_2}[Sn{(OH)_6}]\] . Stannates is the simple oxyanion which is represented by\[Sn{O_3}^{2 - }\] . In some cases, this compound is named as sodium stannate-3-water and represented with the chemical formula \[N{a_2}Sn{O_3}.\,3{H_2}O\] . It is a hydrate with three waters of crystallization.
The anhydrous form of sodium stannate is \[N{a_2}Sn{O_3}\] .
So, alkali metal stannate compounds are prepared by dissolving element tin in a suitable metal hydroxide as in the case of formation of sodium stannate.
\[Sn\,\, + \,\,2NaOH\,\, + \,\,4{H_2}O \to N{a_2}[Sn{(OH)_6}]\,\, + \,\,2{H_2}\]
A similar type of reaction also occurs when tin dioxide is dissolved in base.
\[Sn{O_2}\,\, + \,\,\,2NaOH\,\, + \,\,2{H_2}O \to N{a_2}[Sn{(OH)_6}]\,\]
The anhydrous form can also be prepared by the fusion of tin dioxide with sodium carbonate in a mixed carbon monoxide / carbon dioxide environment.
\[Sn{O_2}\,\, + \,N{a_2}C{O_3}\,\,\, \to \,N{a_2}Sn{O_3}\,\, + C{O_2}\]
The anion of sodium stannate is a coordination complex and it is octahedral in shape just like hexachlorostannate anion \[{[SnC{l_6}]^{2 - }}\]

Note:
Sodium hydroxide \[(NaOH)\] is also known as lye and caustic soda. Remember that when \[Sn\] is fused with \[NaOH\] , sodium stannite \[(N{a_2}Sn{O_2})\] is formed. But in the presence of water, an anhydrous form of sodium stannite i.e. sodium stannate \[(N{a_2}Sn{O_3})\] is formed.