InterviewSolution
Saved Bookmarks
InterviewSolution
| 1. |
(a)Givereasons:20 Reactivity of Al decreases if it is dipped in HNO,(i) Carbon cannot reduce the oxides of Na or Mg.(ii) NaCl is not a conductor of electricity in solid state whereas it does conduct clectricity inaqueous solution as well as in molten state. |
|
Answer» (1) When aluminium is dipped in nitric acid a layer of aluminium oxide is formed on the metal. This happens because nitric acid is a strong oxidizing agent. The layer of aluminium oxide prevents further reaction of aluminium. Due to this, the reactivity of aluminium decreases. (2) This is because sodium and magnesium are more reactive than carbon. This means that carbon cannot reduce the oxides of these metals. The two metals are above carbon in the reactivity series and thus have a high affinity to oxygen than carbon does and thus cannot be reduced by it. (3) NaCl (common salt) is solid in state and solid ions or compounds don't conduct electricity. It needs to be either melted, molten or dissolved in a solution (i.e. water) first. This is because the electrons in a solid state won't be free to move to either the Cathode (-ve) or to the Anode (+ve). |
|