What is the balanced answer for $ NaAl{O_2}\; + \;{H_2}O $ ?

Hint: In this question sodium aluminate and water react to form sodium hydroxide and aluminium hydroxide. This reaction occurs in the basic medium. Balanced equation is the equation in which the number of atoms in the product side is equal to the number of atoms in the reactant side.

Complete answer:
Firstly we will write the complete skeleton equation of the given question. As we know when sodium aluminate and water react, sodium hydroxide and aluminium hydroxide produce. The skeleton equation for this equation is:
 $ NaAl{O_2} + {H_2}O \to Al{\left( {OH} \right)_3} + NaOH $
Now we will balance the equation in following steps:
Step-1: First we will check if the number of sodium present in both sides are equal or not. In this equation they are already equalized. After that we will move to aluminium, this is also already balanced.
  $ NaAl{O_2} + {H_2}O \to Al{\left( {OH} \right)_3} + NaOH $
Step-2: Now we balance the hydrogen and oxygen on both sides. We can see that there are two hydrogen on the reactant side whereas four hydrogen on the product side. Thus we will multiply two in water molecule so that hydrogen molecules on both sides become balance like:
 $ NaAl{O_2} + 2{H_2}O \to Al{\left( {OH} \right)_3} + NaOH $
As we can after balancing the hydrogen atoms, oxygen atoms get balanced themselves. Finally, we will check whether the other elements get unbalanced or not.
The numbers of sodium atoms on both sides are equal similarly the numbers of aluminium atoms are balanced too. Thus the overall equation is balanced. So our balanced equation is:
 $ NaAl{O_2} + 2{H_2}O \to Al{\left( {OH} \right)_3} + NaOH $ .

Note:
The balanced equation follows the law of Conservation of Mass. This is an important guiding principle in science. As we know that a balanced equation lets us predict the amount of reactants needed and amount of products formed. So it is important to balance the chemical equation.