Question

Compose an activity to arrange Ca, Mg and Fe metals in the decreasing order of reactivity with water. Write suitable balanced chemical equation and draw diagrams.
CBSE Class X Science LA (5 Marks)

Answer 1

Activity Procedure :

Take small pieces of metals like ca, Mg and Fe and place separating these metals in beakers  containing small amount of water.

Observation :

If metal reacts with cold water , then reaction rate will be vigorous.

If metal does not react then place the metal in hot water and record the observation.

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3Fe(s) +H2O(l) [Steam]----> Fe3O4 (s) +H2

(g)

Mg(s) +2H2O (l) [hot water]---> Mg(OH)2 ( Aq) +H2(g)

Ca+2H2O(l)[ Cold water] ---> Ca(OH)2 +H2(g)

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metals arranged in decreased order of reactivity is :

Ca>Mg> Fe

Answer 2

step 1:- Take metals calcium (Ca), Magnesium (Mg) and iron (Fe).

step 2:- place separately small pieces of those metals in beakers with small amount of water in them.

step 3:- if the metal react with cold water, then reaction will be vigorous.

if the metal doesn't react with cold water, then treat it with hot water.

step 4:- Record the observations and arrange the metals in decreasing order of reactivity.

we observe :

Ca + 2H2O(cold water) => Ca(OH)2 + H2

Mg + 2H2O (hot water) => Mg(OH)2 + H2

3Fe + 4H2O( steam) => Fe3O4 + 4H2

hence, reactivity order Ca > Mg > Fe