EASY
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Select the incorrect statement with regards to Indigo .

 

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Important Questions on Theoretical Principles of Experimental Chemistry

HARD

Given below are two statements:
Statement-I : Methyl orange is a weak acid.
Statement-II : The benzenoid form of methyl orange is more intense/deeply coloured than the quinonoid form.
In the light of the above statement, choose the most appropriate answer from the options given below:

HARD

A metal chloride X shows the following reactions:

(i) When H2S is passes in an acidified aqueous solution of X a black ppt is a obtained.

(ii) The precipitate obtained in step (i) is not soluble in yellow ammonium sulphide.

(iii) When a solution of stannous chloride is added to an aqueous solution of X,a white precipitate is obtained which turns grey on addition of more of stannous chloride.

(iv) When an aqueous solution of KI is added to an aqueous solution of X, a red precipitate is obtained which dissolves on addition of excess of KI.

Identify X and write down the equations for the reaction at steps (i), (iii) & (iv).

MEDIUM
Ammonium chloride NH4Cls is heated in a test tube. Vapours are brought in contact with a red litmus paper, which changes to blue and then to red. It is because of
HARD

An aqueous solution of an unknown compound X gives the following reactions.

(i) It gives brown precipitate with alkaline KMnO4 solution

(ii) It forms HCl & evolved O2 when reacts with Cl2 gas.

(iii) It liberates I2 from an acidified KI solution.

(iv) It gives orange yellow colour with acidified titanic sulphate solution.

Identify X and give the chemical equations for the reactions (i), (ii) & (iii). 

MEDIUM

Identify the odd one out and justify.

Chloride, nitrate, hydride, ammonium.
 

EASY
A radical with one atom of hydrogen, one atom of carbon and three atom of oxygen is_____.
EASY

Match the following:-

  Column I Column II
  (Elements) (Symbol)
(i) Acidic Radicals K+, Na+
(ii) Basic Radicals Fe2+,Fe3+
(iii) Monovalent Radicals CO32- , SO42-
(iv) Variable Valency Cl-, K+
(v) Tetravalent elements Pb4+, Pt4+

 

MEDIUM
An inorganic salt is lemon yellow in colour. It becomes orange in colour like methyl orange when it is acidic and again becomes yellow when it is alkaline. The inorganic salt will be :
HARD
Give the correct order of initials T or F for following statements. Use T if statement is true and F if it is false.

(i) Cu+ undergoes disproportionation to Cu and Cu2+ in aqueous solution

(ii) Hg2Cl2 does not impart chromyl chloride test

(iii) Sulphide ions react with sodium nitroprusside to form a purple coloured complex. In this reaction, oxidation state of iron changes.