Question

Answer the questions based on the figure below:

1. Which reaction is shown in the figure?
2. Which gas is evolved in the reaction?
3. Give an example of reactants that rapidly show this reaction. Give equations.
4. Give an example of reactants that do not react rapidly.
5. In what condition will reactants of (c) part react? Give equation.

Answer 1

1. Reaction of a metal with water.
2. Hydrogen gas.
3. Sodium and potassium metal react rapidly and vigorously with water and liberate hydrogen gas.
   i. \[\ce{2Na(s) + 2H2O(l) -> 2NaOH(aq) + H2(g) + Heat}\]
   ii. \[\ce{2K(s) + 2H2O(l) -> 2KOH(aq) + H2(g) + Heat}\]
4. The metals: aluminium, iron and zinc.
5. They react with steam to form their oxides. Hydrogen gas is released in this reaction.
   i. \[\ce{2Al(s) + 3H2O(g) -> Al2O3(s) + 3H2(g)}\]
   ii. \[\ce{2Fe(s) + 4H2O(g) -> Fe3O4(s) + 4H2(g)}\]
   iii. \[\ce{Zn(s) + H2O(g) -> ZnO(s) + H2(g)}\]