- Define and explain Acids with Metals and Carbonates in your own words
- Use key terms such as reactivity series accurately
- Apply what you have learned to new examples and questions
- Avoid the common mistakes learners make with this topic
Fizzing indigestion tablets, rusting iron and burning fuels are all chemical changes — new substances made, energy moved. Acids reacting with metals and carbonates follow patterns you can learn once and use forever. In this chapter you will write the equations, make the salts and track the energy.
This lesson focuses on Acids with Metals and Carbonates: write equations for acids reacting with metals and carbonates.
Write equations for acids reacting with metals and carbonates.
Key ideas
Acids react in predictable patterns
Acids react with metals to give a salt plus hydrogen: for example, magnesium + hydrochloric acid → magnesium chloride + hydrogen. With carbonates they give a salt plus water plus carbon dioxide: calcium carbonate + hydrochloric acid → calcium chloride + water + carbon dioxide. Learn these two patterns and you can write the equation for any acid–metal or acid–carbonate reaction.
The reactivity series predicts displacement
A more reactive metal displaces a less reactive one from its compound: iron displaces copper from copper sulfate solution, but copper cannot displace iron. The series also explains extraction — very reactive metals like aluminium need electrolysis, while iron can be extracted by reduction with carbon. Carbon sits in the series as a reference point for these decisions.
Key term — reactivity series: Metals listed in order of reactivity, from potassium (most reactive) to gold (least).
Write the word equation for zinc reacting with dilute sulfuric acid.
Zinc + sulfuric acid → zinc sulfate + hydrogen.
Answer: Zinc + sulfuric acid → zinc sulfate + hydrogen.
- Writing hydrogen as a product of acid + carbonate Acids reacting with carbonates produce carbon dioxide, not hydrogen — hydrogen comes from acids reacting with metals. Mixing these patterns is one of the most common exam errors.
- Forgetting to balance the equation An unbalanced equation does not show that atoms are conserved. Always check that each element appears the same number of times on both sides — for example, 2HCl is needed to supply the 2 chlorines in CaCl₂.
Practice
Endothermic (thermal decomposition): calcium carbonate → calcium oxide + carbon dioxide needs continuous heat input, taking energy from the surroundings.
Iron is more reactive than copper, so it displaces copper from the solution: iron + copper sulfate → iron sulfate + copper. The blue colour fades as brown copper appears.
Yes. Magnesium is more reactive than zinc, so it can take the oxygen from zinc oxide: magnesium + zinc oxide → magnesium oxide + zinc.
Exothermic. More energy is released when the new bonds in CO₂ and H₂O form than is taken in to break the bonds in methane and oxygen.
Quick check
Which of these best defines "reactivity series"?
How would you make pure crystals of copper sulfate from copper oxide and dilute sulfuric acid?
- Acids with Metals and Carbonates: write equations for acids reacting with metals and carbonates.
- Acids react in predictable patterns: Acids react with metals to give a salt plus hydrogen: for example, magnesium + hydrochloric acid → magnesium chloride + hydrogen.
- salt: A compound formed when the hydrogen of an acid is replaced by a metal or ammonium ion, e.g.
- Watch out for: writing hydrogen as a product of acid + carbonate