Question

What is the difference between metal oxide and metal hydroxide?

Answer 1

We have to know that when an oxide group is attached to metal, then such compounds are known as metal oxide. We have to know that when a hydroxide group is attached to metal, then such compounds are known as metal hydroxide. We can give the general representation for metal hydroxide is $MOH$. For metal cation that has divalent charge, the general representation could be $M{\left( {OH} \right)_2}$.

Complete answer:
Three types of oxides are formed by metals and they are,
Metal Oxides
Metal peroxide
Metal superoxide
We can say that metal oxides are crystalline solid that generally contains metal as cation and the anion is oxide.
We have to know that oxide is a dianion of oxygen that has a formula of ${O^{2 - }}$. So, we can say that when an oxide group is attached to metal, then such compounds are known as metal oxide. In metal oxide, the charge/oxidation state of oxide would always be $- 2$.
We have to know that hydroxides of metal are known as metal hydroxides. We can say that metal hydroxides are generally strong bases. We can say in metal hydroxide, the anion is hydroxide and the cation is metal. Similar to metal hydroxide, alkali metal hydroxide gets completely ionized when they are dissolved. Some of the metal hydroxides are weak electrolytes and undergo partial dissociation in aqueous solution.
The major difference between metal oxide and metal hydroxide is that a metal oxide would be formed by the reaction of metal with oxygen and metal hydroxide is formed by the reaction of metal with water.

Note:
We can give the general representation of alkali metal oxide as ${M_2}O$. We can give the general representation of alkaline earth metals as $MO$.We can give the general representation of group $1$ metals as $MOH$. We can give the general representation of group $2$ metals as $M{\left( {OH} \right)_2}$.