When an oxide reacts with an acid, the products are which of the following?

When an oxide reacts with an acid, the products are which of the following?

• A. Salt + water
• B. Salt + hydrogen
• C. Salt only
• D. Water and oxygen

Answer: (A)

When an oxide reacts with an acid, it behaves as a base in an acid–base neutralization. The oxide supplies oxide ions that combine with protons from the acid to form water. The remaining part of the oxide’s cation teams up with the acid’s anion to form a salt. This is why the products are a salt and water. For example, ZnO reacting with HCl gives ZnCl2 and H2O (ZnO + 2HCl → ZnCl2 + H2O). You can picture the oxide washing away the H+ to make water, while the metal part pairs with the chloride to form the salt.

When an oxide reacts with an acid, it behaves as a base in an acid–base neutralization. The oxide supplies oxide ions that combine with protons from the acid to form water. The remaining part of the oxide’s cation teams up with the acid’s anion to form a salt. This is why the products are a salt and water. For example, ZnO reacting with HCl gives ZnCl2 and H2O (ZnO + 2HCl → ZnCl2 + H2O). You can picture the oxide washing away the H+ to make water, while the metal part pairs with the chloride to form the salt.