Which of the following is the correct chemical formula of sodium aluminate?

NaAlO₂

The correct answer is option 1. \(NaAlO_2\).

Sodium aluminate is a compound formed from sodium \((Na)\), aluminum \((Al)\), and oxygen \((O)\). The correct chemical formula for sodium aluminate is \(Na_2AlO_3\). Here's an explanation:

1. Composition:  Sodium aluminate contains sodium ions \((Na^+)\), aluminum ions \((Al^{3+})\), and oxide ions \((O^{2-})\). The compound is formed when sodium hydroxide \((NaOH)\) reacts with aluminum hydroxide \((Al(OH)_3)\), resulting in the formation of sodium aluminate and water:

\[2\text{NaOH} + \text{Al(OH)}_3 \rightarrow \text{Na}_2\text{AlO}_3 + 3\text{H}_2\text{O}\]

2. Chemical Formula:  The formula for sodium aluminate reflects the ratio of the ions present in the compound. Since sodium has a +1 charge \((Na^+)\), aluminum has a +3 charge \((Al^{3+})\), and oxygen has a -2 charge \((O^{2-})\), the chemical formula is determined by balancing the charges of the ions. In this case, two sodium ions \((2Na^+)\) are needed to balance the charge of one aluminum ion \((Al^{3+})\), resulting in the formula \(Na_2Al\). Additionally, three oxide ions \((O^{2-})\) are needed to balance the charge, giving the formula \(Na_2AlO_3\).

3. Use:  Sodium aluminate has various industrial applications, including as a flocculating agent in water treatment, a component in papermaking and pulp production, and a catalyst in the manufacture of zeolites and other chemicals. It is also used in wastewater treatment to remove phosphorus and other contaminants.

In summary, sodium aluminate has the chemical formula \(Na_2AlO_3\), reflecting the presence of two sodium ions \((Na^+)\), one aluminum ion \((Al^{3+})\), and three oxide ions \((O^{2-})\) in the compound. This compound is utilized in several industrial processes due to its flocculating, catalytic, and binding properties.