Question

Using Sodium hydroxide solution, how would you distinguish : Iron (II) chloride from Iron (III) chloride?

Answer 1

Hint: The inorganic compound sodium hydroxide (NaOH) has the formula NaOH. It's a white ionic substance made up of sodium cations $ \text{N}{{\text{a}}^{\text{+}}} $ and hydroxide anions $ \text{O}{{\text{H}}^{\text{-}}} $ . Sodium hydroxide is a caustic base and alkali that decomposes proteins at room temperature and can result in serious chemical burns. It is extremely water soluble and rapidly absorbs moisture and carbon dioxide from the atmosphere.

Complete Step By Step Answer:
The chemical element iron has the symbol Fe and the atomic number 26. It is a metal that belongs to the periodic table's first transition series and group 8. Iron's most frequent oxidation states are iron(II) and iron(III). Iron shares many characteristics with other transition metals, such as ruthenium and osmium, which belong to Group 8. Iron has a wide variety of oxidation states, ranging from -2 to 7.
The chemical compound $ \text{FeC}{{\text{l}}_{\text{2}}} $ stands for iron(II) chloride, commonly known as ferrous chloride. It has a high melting point and is paramagnetic. Although the chemical is white, most samples are off-white. $ \text{FeC}{{\text{l}}_{\text{2}}} $ crystallises as a greenish tetrahydrate from water, which is the most common form seen in commerce and laboratories.
The inorganic chemical with the formula ( $ \text{FeC}{{\text{l}}_{3}} $ ) is iron(III) chloride. It's also known as ferric chloride, and it's a common iron compound with a +3 oxidation state. With a melting point of $ \text{307}\text{.6 }\!\!{}^\circ\!\!\text{ C} $ , the anhydrous chemical is a crystalline solid.
When sodium hydroxide is applied, a filthy green precipitate forms, which eventually becomes reddish brown.
 $ \text{FeC}{{\text{l}}_{2}}(\text{aq})+2\text{NaOH}(\text{aq})\to \text{Fe}{{(\underset{\text{ green }}{\mathop{\text{OH}}}\,)}_{2}}(~\text{s})+2\text{NaCl}(\text{aq}) $
A reddish brown precipitate forms when sodium hydroxide solution is applied.
 $ \text{FeC}{{\text{l}}_{3}}(\text{aq})+3\text{NaOH}(\text{aq})\to \text{Fe}{{(\underset{\text{ brown }}{\mathop{\text{OH}}}\,)}_{3}}(~\text{s})+3\text{NaCl}(\text{aq}) $

Note:
Iron has the chemical features of transition metals, such as the capacity to generate various oxidation states with one-step differences and a broad coordination and organometallic chemistry. The binary halides of ferrous and ferric are well-known. The ferrous halides are generally formed by reacting iron metal with the appropriate hydrohalic acid to produce hydrated salts. The ferric halides are formed when iron interacts with fluorine, chlorine, or bromine, with ferric chloride being the most prevalent.