Final answer:
The anhydride of zinc hydroxide (Zn(OH)2) is zinc oxide (ZnO), which is obtained by removing the hydroxide groups from zinc hydroxide.
The correct answer is 1).
Step-by-step explanation:
The anhydride of zinc hydroxide (Zn(OH)₂) refers to the compound that forms when zinc hydroxide loses its water molecules. To find the anhydride, we need to remove the hydroxide (OH) groups from the zinc hydroxide and see what is left.
Removing two OH groups (which are made up of oxygen and hydrogen) from Zn(OH)₂ would leave us with ZnO, as each OH group contains one oxygen atom, accounting for two oxygens in total, which when removed leave one oxygen atom to combine with the zinc atom.
Therefore, the anhydride of zinc hydroxide is zinc oxide (ZnO).