In this activity, we will observe how metals react when they are burned in air. In the next activity 3.10, we will learn reaction of metals with water.
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.
All Activities Chapter 3 Metals and Non-Metals
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