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Question
Give the balanced equations for the reaction with two different amphoteric oxides with a caustic alkali.
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Solution
Zinc oxide:
\[\ce{\underset{white}{ZnO} + \underset{(colourless soluble)}{\underset{caustic soda}{2NaOH}}-> \underset{sodium zincate}{Na2ZnO2} + H2O}\]
Aluminium oxide:
\[\ce{\underset{white}{Al2O3} + \underset{caustic soda}{2NaOH}->\underset{(white)}{\underset{sodium meta aluminate}{2NaAlO2}} + H2O}\]
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