Which salt is produced when $H _2 SO _4$ reacts with NaOH?
The reaction between sulfuric acid (\(H_2SO_4\)) and sodium hydroxide (\(NaOH\)) is a classic neutralization reaction. In such a reaction, an acid and a base react to form a salt and water. The acid, \(H_2SO_4\), dissociates to provide hydrogen ions (\(H^+\)) and sulfate anions (\(SO_4^{2-}\)). The base, \(NaOH\), dissociates to provide sodium cations (\(Na^+\)) and hydroxide anions (\(OH^-\)).
The salt is formed by the combination of the cation from the base and the anion from the acid. In this case, the cation is the sodium ion (\(Na^+\)) and the anion is the sulfate ion (\(SO_4^{2-}\)). To form a neutral salt, the charges must balance. Since the sodium ion has a charge of \(+1\) and the sulfate ion has a charge of \(-2\), we need two sodium ions for every one sulfate ion. This gives us the chemical formula \(Na_2SO_4\), which is known as sodium sulfate. The full balanced equation for this reaction is \(H_2SO_4 + 2NaOH \rightarrow Na_2SO_4 + 2H_2O\).
Comparing our result, \(Na_2SO_4\), with the given options, we identify that \(Na_2SO_4\) is the correct salt produced. The other options are incorrect: \(K_2SO_3\) and \(K_2SO_4\) contain potassium, and \(Na_2SO_3\) is sodium sulfite, which would be produced if the acid were sulfurous acid (\(H_2SO_3\)) instead of sulfuric acid. Thus, the correct option is \(Na_2SO_4\). Therefore, the final answer is \(\boxed{Na_2SO_4}\).
Neutralization reactions are fundamental in chemistry and everyday life. For example, when you take an antacid tablet to treat heartburn, you are essentially performing a neutralization reaction. Your stomach produces excess hydrochloric acid (\(HCl\)), and the active ingredient in the antacid, such as magnesium hydroxide (\(Mg(OH)_2\)), acts as a base to neutralize the acid, producing a harmless salt (\(MgCl_2\)) and water, thereby relieving discomfort. Understanding these chemical processes helps in everything from pharmaceutical development to managing industrial chemical waste.