Give reasons:1. Gold and Silver are found in their free state.2. Sodium is never found in its' free state.3. The sulphide ore is converted into an oxide for the extraction of metals.4. The oxides of metals like Hg can be reduced by heating only.5. The oxides of metals like Na, Mg, Ca cannot be reduced by Carbon.
Answers
Answer:
1- Au and Ag(gold and silver) have 8 electrons in their outermost shell which means they are balanced and do not need to gain or loose electrons hence they don't combine with any other element or compound.
2- Sodium is very high in the reactivity series which means it can almost combine with every element or displace another element from its compound hence never exists Independently.
3- Sulphide ore is converted into metal oxide because it is easier to extract a metal from its oxide.
4- The metals of oxides can only be reduced by heating because
eg. The oxides of metals like mercury can be reduced by heating only in air.
2HgS + 3O2 = HgO + 2SO2
2HgO = 2Hg + O2
Hence proved.
5- Force of attraction with their oxides is very stable. so the common reducing agent like the 'carbon' cannot reduce these metals from their oxides.That's why carbon not able to reduce oxides fro Na and Mg
this is because metals like platinum,gold and silver are noble metals,they do not easily mix with impurities such as silica,potassium etc. And even if they do mix it can be easily separated by adding a acid to it.Hence, these metals are present in free state.