Transition and InnerTransition Elements - Result Question 94
####21. Which series of reactions correctly represents chemical relations related to iron and its compound?
(2014 Main)
(a) $Fe \xrightarrow{\text { Dil. } H _2 SO _4} FeSO _4 \xrightarrow{H _2 SO _4, O _2} Fe _2\left(SO _4\right) _3 \xrightarrow{\text { Heat }} Fe$
(b) $Fe \xrightarrow{O _2, \text { Heat }} FeO \xrightarrow{\text { Dil. } H _2 SO _4} FeSO _4 \xrightarrow{\text { Heat }} Fe$
(c) $Fe \xrightarrow{Cl _2, \text { Heat }} FeCl _3 \xrightarrow{\text { Heat, air }} FeCl _2 \xrightarrow{Zn} Fe$
(d) $Fe \xrightarrow{O _2, \text { Heat }} Fe _3 O _4 \xrightarrow{CO, 600^{\circ} C} FeO \xrightarrow{CO, 700^{\circ} C} Fe$
Show Answer
Solution:
- PLAN Analyse each reaction given in the question and choose the correct answer on the basis of oxidation state and stability of iron compounds. Use the concept of Ellingham diagram to solve this problem.
The correct reactions are as follows:
(a) $Fe+$ dil. $H _2 SO _4 \longrightarrow FeSO _4+H _2$
$$ \begin{aligned} H _2 SO _4+2 FeSO _4+\frac{1}{2} O _2 & \longrightarrow Fe _2\left(SO _4\right) _3+H _2 O \ Fe _2\left(SO _4\right) _3 \stackrel{\Delta}{\longrightarrow} & Fe _2 O _3(s)+3 SO _3 \uparrow \end{aligned} $$
The given reaction is incorrect in question
