Question

(a) Out of aluminium and silver vessel, which one is more suitable to store 1 M HCl solution and why? 

(b) Element A will reduce the cation of element B but will not reduce the cation of element. Will element C reduces the cation of element B? Explain. 

(c) While H₂O₂ can act as oxidising as well as reducing agent in their reactions, O₃ and HNO₃ acts as oxidants only.

Answer 1

(a) Since reduction potential of silver is more than that of hydrogen, silver vessel will be suitable to store 1M HCl. On the other hand reduction potential of aluminium is less than that of hydrogen so that hydrogen will be liberated if stored in aluminium vessel. 

(b) Since A will reduce B⁺, B has higher reduction potential than A and therefore, B lies above A in the electrochemical series. Now, A will not reduce C⁺, C has lower reduction potential than A and therefore lies below A in electrochemical series. Therefore, C must be below B in series and hence C will reduce B⁺. 

(c) In H₂O₂ oxidation number of 0-1 and can vary from 0 to -2 (+2 is possible in OF₂). The oxidation number can decrease or increase, because of this H₂O₂ can act both oxidising and reducing agent.