Activity 3.9 Class 10 Science

In this activity, we will observe how metals react when they are burned in air.

Reactivity of Metals with Oxygen

Aim of the activity

To compare the reactivity of different metals with oxygen

Materials Required

  1. Pieces of magnesium,aluminium,iron,copper, potassium and sodium

   2.  Spirit lamp

   3. Pairs of tongs

   4. Watch glass

   5. Water

   ⚠️Caution

• Potassium and sodium are extremely reactive and catches fire.
• Activity must be done in the presence of teacher
• User goggles, gloves and tongs 

    Procedure

We take each sample of metal using tongs one by one and burn them. We observe the colour of flame at the time of burning each sample.

We collect the product formed after burning. We add a few drops of water in each collected product and test them with litmus paper.

We also observe the solubility and nature of oxide.

On the basis of observation, we arrange metals in decreasing order of reactivity.

Observation

 

Activity 3.9 – Observation Table

Metal	Ease of Burning	Flame Color	Appearance After Burning	Product Solubility	Nature of Oxide
Magnesium	Burns easily	Bright white flame	White powder (MgO)	Slightly soluble	Basic
Aluminium	Burns with difficulty	White spark/flame	White ash (Al₂O₃)	Insoluble	Basic
Zinc	Needs strong heating	Bluish-green flame	Yellow when hot, white when cool	Insoluble	Basic
Iron	Sparks, doesn't burn easily	Golden sparks	Black residue (Fe₃O₄)	Insoluble	Basic
Copper	Hard to burn	Green flame	Black coating (CuO)	Insoluble	Basic

 

Explanation

Potassium and sodium are highly reactive metals and form strong basic oxides. Magnesium, iron and aluminium are less reactive than K and Na.

Copper reacts very slowly.

Reactivity Series

 K > Na > Mg > AI > I >Cu

 

Conclusion

This activity explains that most of the metal oxides are basic in nature. Aluminium oxide is amphoteric (both acidic and basic) in nature. The activity also shows the reactivity of metals with oxygen.

Frequently Asked Questions

    1. Which metals catch fire in the air?

Answer – Potassium and sodium catch fire in the air because they are highly reactive.

    2. What is the nature of potassium and sodium oxide?

Answer- They are strongly basic in nature.

  3. Which metal is less reactive with oxygen in this activity?

Answer – Copper

   4. Which metal oxides are soluble in water?

Answer – Potassium oxide and sodium oxides are soluble in water.