Activity 3.10 Class 10 Science

In this activity, we will study the reaction of metals with water and arrange the metals in order of reactivity with water.

Reactivity of Metals with Water

Aim of the activity

To study how metals react with water

Materials Required

   1. Sample pieces of K,Na,Ca,Mg,Al,Zn,Fe,Cu

   2. Cold water, hot water and steam

   3. Beakers

   4. Tongs

   5. Match box

    6. Safety goggles and gloves

Procedure

We take small pieces of metals and put them into separate beakers half filled with cold water. Now we observe formation of bubbles, fire and metal floating.

Now we repeat the same test with hot water for those metals that didn’t react with cold water.

And finally, we test with steam for those metals that didn’t react even with hot water.

 

Observation

On the basis of the above experiment, we observe

Explanation

Sodium and potassium reacts with cold water violently and catch fire.

 2K+ H₂O →2KOH + H₂ + heat energy

 2Na + H₂O →2NaOH + H₂ + heat energy

Calcium also reacts with cold water and floats due to formation of hydrogen gas bubbles.

 Ca +  + 2H₂O →Ca(OH)₂ + H₂

 

Magnesium and zinc react with hot water.

  Mg+  + 2H₂O →Mg(OH)₂ + H₂

 

 Aluminium and iron react slowly with steam.

   2Al+ 3H₂O → Al₂O₃  + 3H₂

 

Copper does not react with water or steam.

 

Order of reactivity of the given metals with water is:

K > Na > Ca > Mg > AI > Zn > Fe > Cu

Conclusion

This activity demonstrates that metals show different

levels of reactivity with water. Some metals are highly

reactive and some are moderate.

Frequently Asked Questions

    1. Which metal catch fire with cold water?

Answer – Potassium and sodium

 

    2. Why do some metals float on water?

Answer – because hydrogen gas is formed and stick to the metal so metals float.

   

    3. Which metal does not react with water?

Answer - Copper

   4. Which gas is produced when metals react with water?

Answer- Hydrogen gas

   5. Why doesn’t aluminium react with water?

Answer – Aluminium has an oxide layer that prevents the  reaction with water.