- Acids react with metals that is more electropositive than hydrogen in the electrochemical series to produce salt and hydrogen gas.
- Acids do not react with copper and silver.
- This is actually a displacement, where the metals that are placed above hydrogen in Electrochemical Series displace hydrogen from acid.
Acids + Reactive Metal → Salt + Hydrogen Gas
Example:
Sulphuric acid + Zinc
H2SO4 + Zn → ZnSO4 + H2
Nitric acid + Lead
2HN3 +Pb→Pb (NO3)2 + H2
Example of Experiment
Procedure
- About 5 cm³ of dilute sulphuric acid is poured into a test tube.
- One spatula of zinc powder is added into the acid.
- A burning wooden splinter is placed at the mouth of the test tube.
- The observations are recorded.
Observation
Colourless gas is released. A “pop” sound produced when the wooden splinter is placed at the mouth of the test tube.
Inference
Hydrogen gas is released
Chemical Equation
H2SO4 + Zn → ZnSO4 + H2