Question

Name the substance which remains in a test tube after heating ferrous sulphate-
A. $F{e_2}{O_3}$
B. $F{e_2}S$
C. $F{e_2}{\left( {S{O_4}} \right)_3}$
D. None of these

Answer 1

Hint- Iron (II) sulphate or ferrous sulphate means a range of salts with the formula $FeS{O_4}.x{H_2}O$. These compounds exist most generally as the heptahydrate (x = 7) yet are known for a few values of x. The hydrated structure is utilized restoratively to treat iron inadequacy, and furthermore for industrial applications.

Complete answer:
Referred to since ancient times as copperas and as green vitriol (vitriol is an archaic name for sulphate), the blue-green heptahydrate (hydrate with 7 particles of water) is the most widely recognized type of this material. All the iron (II) sulphates disintegrate in water to give the equivalent aquo complex ${\left[ {Fe{{\left( {{H_2}O} \right)}_6}} \right]^{2 + }}$, which has octahedral molecular geometry and is paramagnetic. The name copperas dates from times when the copper (II) sulphate was known as blue copperas, and maybe in similarity, iron (II) and zinc sulphate were referred to individually as green and white copperas.
Warming ferrous sulphate in a test tube, following reaction will happens:
$
  FeS{O_4}.7{H_2}O \to FeS{O_4} + 7{H_2}O \\
  2FeS{O_4} \to F{e_2}{O_3} + S{O_2} + S{O_3} \\
$
Both SO₂ that is sulphur dioxide and SO₃ that is sulphur trioxide, are gases that are colourless and evolved out.
Just $F{e_2}{O_3}$, that is ferric oxide which is reddish brown in colour and stays in the test tube.
So, the correct response is $F{e_2}{O_3}$, that is ferric oxide which is reddish brown in colour and stays in a test tube subsequent to warming ferrous sulphate.

Thus, option A is the correct option.

Note: Along with other iron compounds, ferrous sulphate is utilized to fortify foods and to treat and forestall iron inadequacy weakness. Constipation is a regular and awkward symptom related with the administration of oral iron supplements. Stool softeners frequently are endorsed to forestall constipation.