What Is the Reactivity Series and How Is Metal Reactivity Determined
The reactivity series is essential in chemistry and helps students understand various practical and theoretical applications related to this topic. Whether you are preparing for school exams or want to know why certain metals rust or extract differently, learning the reactivity series provides great clarity for chemical reactions and real-world examples.
This concept also appears across many chapters and is a foundation for various types of chemistry questions.
What is Reactivity Series in Chemistry?
A reactivity series refers to the arrangement of metals in the order of their reactivity, from the highest to the lowest. This concept appears in chapters related to displacement reactions, metallic and non-metallic minerals, and metals and non-metals, making it a foundational part of your chemistry syllabus.
The reactivity series helps us predict the behavior of metals in reactions with water, acids, and salts and is particularly helpful for understanding concepts like rusting, corrosion, and extraction of metals.
Standard Reactivity Series Table
The reactivity series of metals lists metals from most to least reactive. It is a quick reference for predicting chemical changes, especially in reactions involving metals, water, and acids.
| Reactivity Order | Element (Symbol) | Notable Feature |
|---|---|---|
| 1 (Most Reactive) | Potassium (K) | Reacts violently with water |
| 2 | Sodium (Na) | Reacts quickly with water |
| 3 | Calcium (Ca) | Reacts with cold water |
| 4 | Magnesium (Mg) | Reacts with hot water/steam |
| 5 | Aluminium (Al) | Forms protective oxide layer |
| 6 | Zinc (Zn) | Corrodes easily |
| 7 | Iron (Fe) | Prone to rusting |
| 8 | Lead (Pb) | Reacts slowly with acids |
| 9 | Hydrogen (H) | Reference (non-metal) |
| 10 | Copper (Cu) | Rarely reacts, forms green patina |
| 11 | Mercury (Hg) | Very weak reactivity |
| 12 | Silver (Ag) | Does not react with acids easily |
| 13 | Gold (Au) | Does not corrode |
| 14 (Least Reactive) | Platinum (Pt) | Most resistant |
How to Remember: Reactivity Series Mnemonics & Tricks
Many students use memory tricks to learn the reactivity series easily. Here are some popular sentences:
- Please Stop Calling Me A Zebra In Lovely Happy Cities - Smart Girls Please!
(Potassium, Sodium, Calcium, Magnesium, Aluminium, Zinc, Iron, Lead, Hydrogen, Copper, Silver, Gold, Platinum) - Another simple one: "Peter Sells Cars Made And Zinc In Large Heavy Cages, Securely Guarded by Plato."
- Make your own fun rhyme for quick revision before your exams!
Understanding the Reactivity Pattern
Metals at the top of the series lose electrons the easiest, which makes them highly reactive. This is why potassium and sodium react quickly with water or air. As you go down, the attraction between the metal’s outermost electrons and nucleus increases, so losing electrons becomes harder and the reactivity drops. This is also why gold and platinum barely react and are used for jewelry and electrical contacts.
Applications & Examples
The reactivity series is used in many practical and exam-based scenarios:
- Predicting displacement reactions (e.g., zinc can displace copper from copper sulphate: Zn + CuSO₄ → ZnSO₄ + Cu)
- Selecting methods for extraction of metals from ores
- Understanding corrosion and rusting of iron
- Explaining which metals produce hydrogen with acids (those above hydrogen in the series do)
- Lab experiments involving single displacement reactions
Reactivity Series of Non-Metals
While the main reactivity series is for metals, non-metals like halogens (fluorine, chlorine, bromine, iodine) also have their own reactivity pattern. For halogens, reactivity decreases down the group: Fluorine > Chlorine > Bromine > Iodine. This is often discussed when learning about properties of non-metals and their chemical behavior.
Try This Yourself
- Use the reactivity series to predict: Will magnesium displace iron from iron sulphate solution?
- Name two metals that won’t react with dilute hydrochloric acid.
- Write the balanced equation when zinc is put in copper sulphate solution.
- Remember a mnemonic and recite the order without looking!
Lab or Experimental Tips
Remember, always add small pieces of highly reactive metals (like sodium or potassium) to water gently and use tongs in experiments. In Vedantu live classes, teachers use colored charts or model kits to help you quickly identify metal order and predict outcomes of reactions like displacement or corrosion.
Frequent Related Errors
- Confusing metals that are close together in the series (e.g., confusing copper and silver positions).
- Forgetting that hydrogen is included just for reference, even though it is not a metal.
- Assuming all metals react with acids – in reality, those below hydrogen in the series do not.
- Using wrong mnemonics and mixing up the order during quick revision or in MCQs.
- Believing that a metal’s hardness determines reactivity – it actually depends on electron loss tendency.
Uses of Reactivity Series in Real Life
The reactivity series is widely used to explain why iron rusts, why gold and platinum do not corrode, and why zinc is used for stabilizing or protecting iron from rusting (galvanization). It is also critical in how metals are extracted and separated during industrial and laboratory processes.
Relation with Other Chemistry Concepts
The reactivity series is closely related to electrochemical series and redox reactions, helping students bridge the gap to learn about electron transfer, oxidation-reduction, and applications in batteries and extraction industry. Understanding the position of a metal will also help with periodic table trends and properties.
Step-by-Step Reaction Example
1. Write the reaction: When zinc is placed into a copper sulphate solution.2. Balanced equation: Zn(s) + CuSO₄(aq) → ZnSO₄(aq) + Cu(s)
3. Zinc is higher in the reactivity series, so it replaces copper.
4. The blue color of copper sulphate fades as copper metal forms and settles.
5. This demonstrates single displacement, predicted using the reactivity series.
Final Wrap-Up
We explored reactivity series—its order, patterns, practical usage, and importance in chemical reactions and metal extraction. Understanding this topic not only helps predict chemical outcomes but also builds a strong foundation in chemistry. For more in-depth lessons, practical tricks, and exam-winning strategies, keep exploring notes and live sessions on Vedantu.
FAQs on Reactivity Series of Metals and Their Chemical Reactivity
1. What is the reactivity series in chemistry?
The reactivity series is a list of metals arranged in order of decreasing reactivity, showing how readily they lose electrons to form positive ions. It helps predict displacement reactions and metal extraction methods.
- Metals at the top react more vigorously (e.g., potassium, sodium).
- Metals at the bottom are less reactive (e.g., copper, silver, gold).
- It is also called the activity series of metals.
2. What is the correct order of metals in the reactivity series?
The correct order of the reactivity series of metals from most reactive to least reactive is: potassium, sodium, calcium, magnesium, aluminium, zinc, iron, tin, lead, hydrogen, copper, silver, gold.
- Most reactive: K > Na > Ca
- Moderately reactive: Mg > Al > Zn > Fe
- Less reactive: Pb > (H) > Cu > Ag > Au
3. Why is hydrogen included in the reactivity series?
Hydrogen is included in the reactivity series to compare metals based on their ability to displace hydrogen from acids. Metals above hydrogen can liberate hydrogen gas from dilute acids, while those below cannot.
- Example: Zn(s) + 2HCl(aq) → ZnCl2(aq) + H2(g)
- Copper, which is below hydrogen, does not react with dilute hydrochloric acid.
4. How does the reactivity series help predict displacement reactions?
The reactivity series predicts that a more reactive metal will displace a less reactive metal from its compound. If a metal is higher in the series, it can replace a metal lower in the series from a salt solution.
- Example: Zn(s) + CuSO4(aq) → ZnSO4(aq) + Cu(s)
- Zinc is above copper, so displacement occurs.
- If reversed, no reaction occurs.
5. How do metals react with water in the reactivity series?
Metals high in the reactivity series react vigorously with water to form metal hydroxides and hydrogen gas. The reactivity decreases down the series.
- Potassium: 2K(s) + 2H2O(l) → 2KOH(aq) + H2(g)
- Calcium: Ca(s) + 2H2O(l) → Ca(OH)2(aq) + H2(g)
- Magnesium reacts slowly with cold water but faster with steam.
6. How do metals react with acids according to the reactivity series?
Metals above hydrogen in the reactivity series react with dilute acids to produce a salt and hydrogen gas. Metals below hydrogen do not displace hydrogen from acids.
- General reaction: Metal + Acid → Salt + H2(g)
- Example: Mg(s) + 2HCl(aq) → MgCl2(aq) + H2(g)
7. How is the reactivity series related to metal extraction?
The reactivity series determines the method used to extract metals from their ores. Highly reactive metals require electrolysis, while less reactive metals can be reduced using carbon.
- Above carbon (e.g., K, Na, Ca, Mg, Al): extracted by electrolysis.
- Below carbon (e.g., Zn, Fe, Pb): extracted by reduction with carbon.
- Very low reactivity (e.g., Au, Ag): found native in nature.
8. What is the difference between the reactivity series and the electrochemical series?
The reactivity series is an empirical arrangement of metals based on observed chemical reactions, while the electrochemical series is based on standard electrode potentials (E° values).
- Reactivity series: qualitative and used in basic chemistry.
- Electrochemical series: quantitative and used in redox calculations.
- Electrochemical series includes standard reduction potentials measured in volts.
9. Why are potassium and sodium at the top of the reactivity series?
Potassium and sodium are at the top of the reactivity series because they lose their single valence electron very easily to form positive ions. Their low ionization energy makes them highly reactive.
- They form K+ and Na+ readily.
- They react violently with water and must be stored in oil.
10. Can you give an example of a displacement reaction using the reactivity series?
A classic example of a displacement reaction is iron displacing copper from copper(II) sulfate solution. The balanced equation is: Fe(s) + CuSO4(aq) → FeSO4(aq) + Cu(s).
- Iron is above copper in the reactivity series.
- The blue CuSO4 solution turns green due to FeSO4 formation.
- Reddish-brown copper metal is deposited.
