Reactivity series

What is the full order of the reactivity series including hydrogen?

Potassium (K), Sodium (Na), Calcium (Ca), Magnesium (Mg), Aluminium (Al), Zinc (Zn), Iron (Fe), Hydrogen (H), Copper (Cu), Silver (Ag), Gold (Au).

Give a mnemonic to remember the reactivity series including hydrogen.

King Nathan’s Cat Maggie Always Zooms Fast. Henry Clutches Angry Angus.

Define the reactivity series.

The reactivity series is a list of metals arranged in order of decreasing reactivity, showing their ability to lose electrons and form positive ions.

Why is hydrogen included in the reactivity series?

Hydrogen is included as a reference point to compare metals’ ability to react with acids and water.

Predict whether potassium reacts with water and write the balanced equation.

Potassium reacts vigorously with cold water, producing potassium hydroxide and hydrogen gas. Equation: 2K (s) + 2H₂O (l) → 2KOH (aq) + H₂ (g)

Which metals react with cold water and what do they produce?

Potassium, sodium, and calcium react with cold water to produce metal hydroxides and hydrogen gas.

Write the equation for magnesium reacting with steam.

Mg (s) + H₂O (g) → MgO (s) + H₂ (g)

Explain why aluminium does not react with water easily despite being high in the reactivity series.

Aluminium forms a strong, protective oxide layer on its surface that prevents further reaction with water or air.

Which metals react with dilute acids to produce hydrogen gas?

Metals above hydrogen in the reactivity series such as magnesium, zinc, and iron react with dilute acids to produce hydrogen gas and metal salts.

Write the equation for zinc reacting with dilute hydrochloric acid.

Zn (s) + 2HCl (aq) → ZnCl₂ (aq) + H₂ (g)

Why do metals below hydrogen not react with acids to produce hydrogen?

They are less reactive than hydrogen and cannot displace hydrogen from acids.

Describe and explain a displacement reaction using the reactivity series.

A more reactive metal displaces a less reactive metal from its compound in solution. For example, zinc displaces copper from copper sulfate. Equation: Zn (s) + CuSO₄ (aq) → ZnSO₄ (aq) + Cu (s)

Write the ionic equation for zinc displacing copper from copper sulfate.

Zn (s) + Cu²⁺ (aq) → Zn²⁺ (aq) + Cu (s)

Explain how the reactivity series determines metal extraction methods.

Highly reactive metals require electrolysis of molten compounds for extraction; less reactive metals can be extracted by reduction with carbon.

Explain why gold is found as a native metal.

Gold is very unreactive and does not easily form compounds; it remains in elemental form in the earth.

How does the reactivity series predict metal corrosion?

Metals high in the series corrode easily because they oxidize quickly, forming oxides or hydroxides.

Give an example of a metal reacting with oxygen and write the equation.

Magnesium burns in oxygen to produce magnesium oxide. Equation: 2Mg (s) + O₂ (g) → 2MgO (s)

Write a balanced equation for iron reacting with dilute sulfuric acid.

Fe (s) + H₂SO₄ (aq) → FeSO₄ (aq) + H₂ (g)

Explain what happens when a metal reacts with water and acid in terms of electron transfer.

Metal atoms lose electrons (oxidation) to form positive ions; electrons reduce H⁺ ions to hydrogen gas.

Why does magnesium react faster with acid than iron?

Magnesium is more reactive and loses electrons more readily, so it reacts faster with H⁺ ions.

How can the reactivity series be experimentally determined?

By testing metals with acid or water and observing hydrogen gas evolution or displacement reactions.

Write the general reaction for a metal displacing hydrogen from an acid.

Metal (M) + 2H⁺ (aq) → M²⁺ (aq) + H₂ (g)

What is the role of carbon in metal extraction?

Carbon acts as a reducing agent removing oxygen from metal oxides.

Give an example and equation of metal extraction using carbon.

Extraction of iron from iron oxide using carbon monoxide. Equation: Fe₂O₃ (s) + 3CO (g) → 2Fe (s) + 3CO₂ (g)

Why do metals high in the reactivity series not get extracted by carbon reduction?

Their oxides are too stable for carbon to reduce; electrolysis is used instead.

How does the reactivity series explain why zinc can displace copper from copper sulfate solution?

Zinc is more reactive, loses electrons, forming Zn²⁺ ions; copper ions gain electrons and deposit as copper metal.

What safety precautions should be taken when testing metal reactivity with acids?

Wear goggles, use dilute acid, work in a ventilated area, and handle reactive metals carefully.

Explain why aluminium does not react with dilute acid as readily as magnesium despite being above hydrogen.

Aluminium’s oxide layer protects the metal from acid attack.

What is the ionic equation for magnesium reacting with hydrochloric acid?

Mg (s) + 2H⁺ (aq) → Mg²⁺ (aq) + H₂ (g)

What observations indicate a metal is reacting with acid?

Bubbling due to hydrogen gas, metal dissolving, and temperature rise.

What is a displacement reaction?

A reaction where a more reactive metal displaces a less reactive metal from its compound.

Why does copper not react with dilute hydrochloric acid?

Copper is less reactive than hydrogen and cannot displace hydrogen ions.

How is the reactivity series useful in predicting the products of redox reactions involving metals?

It predicts which metals will oxidize (lose electrons) or reduce (gain electrons) in reactions.

How does the reactivity series relate to the electrochemical series?

Both rank metals by their tendency to lose electrons; electrochemical series uses standard electrode potentials.