Question

Name four metals which react with caustic soda or caustic potash solution on boiling and liberate hydrogen gas.Support your answer writing an chemical equation for any one of the above named metals?

Answer 1

Four metals which react with caustic soda or caustic potash solution on boiling and liberate hydrogen gas are :

• Zinc (Zn)  
• Aluminium (Al)
• Tin (Sn)
• Beryllium(Be)

• Zinc reacts with boiling aqueous caustic soda to form Sodium Zincate and liberate hydrogen gas.

• Aluminium reacts with boiling aqueous caustic soda to form Sodium Aluminate and liberate hydrogen gas.

• Tin reacts with aqueous caustic soda to form Sodium Stannate and hydrogen gas
• Zn and Al also reacts with caustic potash.

The chemical reaction between Zinc and boiling aqueous caustic soda is described by the following reaction :

                           Zn + 2NaOH(aq) -----> Na₂ZnO₂ +H₂(g)