( c) ____iron is the purest form of iron.

Options

A. Steel
B. Wrought iron
C. Cast iron
D. Pig iron

Answer

b

Explanation

Wrought iron is the perest of iron (and thus has highest melting point) while can is the implest form of iron and then has iron and has lower melting point carbon of steel is in between that lower of cast of pig iron and wrong ht iron .The increasing order of implarty is
Winoght iron lt and lt pig iron cast iron.
The molten metel obtained from the blast furnace is known as pig iron. It contains up to `4.3%` carbon and possible other impurities such as `Si,P, S` and `Mn` , The non-metallic other impurities must be removed to redcue the brittlensess.
The souce of the impurities in pig iron are as follows : `C` arises from the coke used in the blast furnace `Si, P and S` originate form the reduction by `C` of silicates, phosphates or sulphates present in the ore, or from `S` in the coke. Small amounts of `Mn` are often found in iron ore, but for most purpose this is beneficial rather than harmful.
Cast irons (which contain as high as `4.5%` carbon) is made by igniting a minuts of pig iron scrrap iron and coke in cuipole farance by a blast of jhot air .The remethed non is present into moduls to make article such as mathols covers gatting reachinary frames and draimpipes cast iron example slightly on solusiying and therefore farthfully reproductes the slight on the moudle ,it is extremely hard , but unifortanatelly is very bettle and will fraction if struch by a sharp blow . The imprtities in cast iron lower the melting point from `1538^(@)C` for pure iron to appoximatelly `1200^(@)C`.
Wrough iron is made by heating impure iron (pig iron or cast iron) with bacamatile so that impurities are oxidired carbon is converted tyo carbon monoxide while silicon and manganece to a slag
`Fe_(2)O_(3)(s) + 3C(s) rarr 2Fe(1) + 2CO(g)`
`2Fe_(2)O_(3)(s) + 3Si(s) rarr 4Fe(1) + 3SiO_(2)`
`Fe_(2)O_(3)(s)+3Mn(s)rarr2Fe(1)+3 MnO`
` MnO + SiO(2)tounderset(slag)(MnSiO_(3))`
As the impurities are removed , the melting point of the iron rises to about `1500^(@)C` and the pasty mass is removed from the furance as balls and worked under a hammer to squezze out the slag.
Wrought iron is tough mallcable , railway carriage coupling and ormamebtal gates etc wronght iron , which is ressistant to rusting and corrosion due to the presence of `MnSiO_(2)` and `FePO_(4)` slag etc wrong iron used to present partly as iron , (pig iron cast iron) is too britle for most perpose and is converted into steel by removing practically all the `S,Si and P` impurities. The carbon content of impure iron, which may be a high as `4.5%_(0)`, is reduced to between `0.1` and `2.0` percent depending on the type of steel required.