Explain the following
i. Reactivity of Al decreases if it is dipped in HNO3.
ii. NaCl is not a conductor of electricityin solid state,whwereas it does conduct electricity in aqueous solution as well as in molten state.
iii. Iron articles are galvanised.
iv. Metals like Na,K,Ca and Mg are never found in their free state in
nature.
Answers
Answer:
i. Reactivity of Al decreases if it is dipped in HNo3 because it forms Al(No3)3 which is less reactive due to the formation of oxide layer over the compound.
ii. NaCl is not a conductor of electricity in solid state, whereas it does conduct electricity in aqueous solution as well as in molten state because in solid state as the molecules are packed very close to each other, so there is no availability of free or mobile ions.
iii. Iron articles are galvanised as they are more reactive to atmospheric moisture and oxygen. Therefore rusting may take place and the article get corroded.
iv. Metal like Na,K,Ca and Mg are never found in their free state in nature because they are placed on the top of the reactivity series as they are highly reactive metals.
Explanation: