Acid + metal →

## **The reasoning** When an acid reacts with a **metal**, it's a **displacement reaction**. The metal "kicks out" the hydrogen from the acid, taking its place to form a salt, while hydrogen gas bubbles off. **General equation:** Acid + Metal → Salt + Hydrogen gas (H₂) **Example:** Hydrochloric acid + Zinc → Zinc chloride + Hydrogen HCl + Zn → ZnCl₂ + H₂↑ The metal donates electrons to the H⁺ ions in the acid, releasing H₂ gas (you'll see fizzing/bubbles). What remains is the metal combined with the acid's anion—that's your salt. ## **Why the wrong options tempt you** **A) Salt + water** — This is what you get from *acid + base* (neutralization). Don't mix up metal reactions with neutralization! **C) Salt + CO₂** — This happens with *acid + carbonate* (like vinegar + baking soda). Different reactant entirely. **D) Salt + oxygen** — Metals don't produce oxygen with acids. This confuses combustion reactions. ## **Quick takeaway** **Metal + Acid = Salt + Hydrogen gas** — think of the metal "freeing" hydrogen from the acid's grip, creating fizzy bubbles!