Which of the options represents the correct and balanced chemical equation for the reaction between a metallic oxide and an acid?  

CuO + HCl → ______ + ________

The correct answer is CuO + 2HCI → CuCl2 + H2O.

Key Points

• When a metallic oxide reacts with an acid, it typically forms a salt and water.
• Copper (II) oxide (CuO) is a black solid that reacts with hydrochloric acid (HCl) to form copper (II) chloride (CuCl2), a greenish-blue solution, and water (H2O).
• The balanced chemical equation for this reaction is CuO + 2HCl → CuCl2 + H2O.
• Balancing the equation ensures that the number of atoms of each element is the same on both sides of the equation, adhering to the law of conservation of mass.

Additional Information

• Metallic Oxides:
  • Metallic oxides are compounds consisting of a metal and oxygen.
  • They are typically basic and react with acids to form salts and water.
• Hydrochloric Acid (HCl):
  • Hydrochloric acid is a strong acid, commonly used in various chemical reactions.
  • It is highly corrosive and should be handled with care.
• Balancing Chemical Equations:
  • Balancing chemical equations is essential for representing the law of conservation of mass.
  • It ensures that the number of atoms for each element is equal on both the reactant and product sides.
• Copper (II) Chloride (CuCl2):
  • Copper (II) chloride is an inorganic compound with the formula CuCl2.
  • It appears as a greenish-blue solid and is used in various industrial and chemical applications.