
The compound which is responsible for the green colour formed when \[S{O_2}\] is bubbled through acidified potassium dichromate solution is:
A.Nitroso iron [II] sulphate
B.Iron [III] chloride
C.Chromium sulphate
D.Lead [II] chloride
Answer
489k+ views
Hint: When sulphur dioxide gas is passed through an acidified potassium dichromate solution, potassium dichromate gets reduced to its sulphate by redox reaction. This is a green coloured solution formed from orange dichromate solution.
Complete step by step answer:
The chemical reaction between acidified potassium dichromate and sulphur dioxide gas is characterised by colour change, from orange of dichromate to green of chromium sulphate. Sulphur dioxide gas reduces acidified potassium dichromate from \[C{r_2}O_7^{2 - }\](orange) to \[C{r^{3 + }}\](green) ions without leaving a residue and itself oxidized from \[SO_3^{2 - }\]ions in sulphuric acid to \[SO_4^{2 - }\]ions in the same acid.
\[{K_2}C{r_2}{O_7} + {H_2}S{O_4} + 3S{O_2} \to {K_2}S{O_4} + C{r_2}{(S{O_4})_3} + {H_2}O\]
Here, the oxidising agent is potassium dichromate while the reducing agent is sulphur dioxide. This results in a redox reaction. The orange-coloured dichromate solution will turn green due to the formation of chromium sulphate, \[C{r_2}{(S{O_4})_3}\]. Sulphuric acid is used as a dehydrating agent here.
Hence, the correct option is (C).
Additional information:
Potassium dichromate is an inorganic chemical reagent used as an oxidizing agent in chemical laboratories. It can oxidize alcohol into aldehydes and further carboxylic acid.
Note:
This reaction is a specific reaction used as a test for sulphur dioxide gas. If a filter paper is impregnated with potassium dichromate solution and it turns green, sulphur dioxide may be present (reduction of chromium(VI) to chromium(III)).
Complete step by step answer:
The chemical reaction between acidified potassium dichromate and sulphur dioxide gas is characterised by colour change, from orange of dichromate to green of chromium sulphate. Sulphur dioxide gas reduces acidified potassium dichromate from \[C{r_2}O_7^{2 - }\](orange) to \[C{r^{3 + }}\](green) ions without leaving a residue and itself oxidized from \[SO_3^{2 - }\]ions in sulphuric acid to \[SO_4^{2 - }\]ions in the same acid.
\[{K_2}C{r_2}{O_7} + {H_2}S{O_4} + 3S{O_2} \to {K_2}S{O_4} + C{r_2}{(S{O_4})_3} + {H_2}O\]
Here, the oxidising agent is potassium dichromate while the reducing agent is sulphur dioxide. This results in a redox reaction. The orange-coloured dichromate solution will turn green due to the formation of chromium sulphate, \[C{r_2}{(S{O_4})_3}\]. Sulphuric acid is used as a dehydrating agent here.
Hence, the correct option is (C).
Additional information:
Potassium dichromate is an inorganic chemical reagent used as an oxidizing agent in chemical laboratories. It can oxidize alcohol into aldehydes and further carboxylic acid.
Note:
This reaction is a specific reaction used as a test for sulphur dioxide gas. If a filter paper is impregnated with potassium dichromate solution and it turns green, sulphur dioxide may be present (reduction of chromium(VI) to chromium(III)).
Recently Updated Pages
Master Class 12 Economics: Engaging Questions & Answers for Success

Master Class 12 Maths: Engaging Questions & Answers for Success

Master Class 12 Biology: Engaging Questions & Answers for Success

Master Class 12 Physics: Engaging Questions & Answers for Success

Master Class 12 Business Studies: Engaging Questions & Answers for Success

Master Class 12 English: Engaging Questions & Answers for Success

Trending doubts
The probability that a leap year will have only 52 class 12 maths CBSE

Describe the poetic devices used in the poem Aunt Jennifers class 12 english CBSE

What does the god that failed refer to class 12 english CBSE

Which country did Danny Casey play for class 12 english CBSE

The final image formed by a compound microscope is class 12 physics CBSE

Why was the Moral Rearmament Army welcomed at the class 12 english CBSE
