Give reasons for the following: a. Copper cannot displace zinc from its salt solution. b. Sodium and potassium are stored in kerosene
Answers
Answer:
a) In the reactivity series, zinc is more reactive than copper. A more reactive metal can replace a less reactive metal, but a less reactive metal cannot replace a more reactive metal. Thus, copper cannot displace zinc from its salt solution, while zinc can displace copper from its salt solution.
b) Sodium and Potassium are highly reactive metals and react vigorously with the oxygen, carbon dioxide and moisture present in the air such that it may even cause a fire. To prevent this explosive reaction, Sodium is kept immersed in kerosene because Sodium doesn't react with kerosene.
Answer:
(a)Sodium and potassium are the most reactive metals. They are stored in kerosene because they react very vigrously with air and water because of the presence of oxygen. If they come in contact with oxygen then it will react and will form sodium hydroxide. And kerosene is a alkanes and don't react much.. that's why sodium and potassium are stored in kerosene.
(b) Yes, copper cannot displace zinc from it's zinc sulphate solution. As we know zinc is more reactive metal as compared to copper. And in displacement reaction, a more reactive metal displaces a less reactive metal from its solution. But copper is less reactive than zinc so how it can displace zinc .. that's why copper cannot displace zinc from it's zinc sulphate solution.