MEDIUM
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Brown ring test is used for detection of:

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Important Questions on Theoretical Principles of Experimental Chemistry

HARD
A white precipitate was formed when BaCl2 was added to water extract of an inorganic salt. Further, a gas 'X' with characteristic odour was released when the formed white precipitate was dissolved in dilute HCI. The anion present in the inorganic salt is:
EASY
In the detection of II group acid radical, the salt containing chloride is treated with concentrated sulphuric acid, the colourless gas is liberated. The name of the gas is
MEDIUM

Match List I with List II.

  List-I
(Anion)
  List-II
(gas evolved on reaction with dil. H2SO4)
(A) CO32- (I)

Colourless gas which turns lead acetate paper black.

(B) S2- (II)

Colourless gas which turns acidified potassium dichromate solution green.

(C) SO32- (III) Brown fumes which turns acidified KI solution containing starch blue.
(D) NO2- (IV) Colourless gas evolved with brisk effervescence, which turns lime water milky.

Choose the correct answer from the options given below

HARD

Distinguish between the following pair of compounds using a reagent as a chemical test:

  • Magnesium chloride and magnesium nitrate solution.
EASY
On heating, lead (ll) nitrate gives a brown gas (A). The gas (A) on cooling changes to a colourless solid/liquid (B). (B) on heating with NO changes to ablue solid (C). The oxidation number of nitrogen in solid (C) is:
MEDIUM
When a solution of mixture having two inorganic salts was treated with freshly prepared ferrous sulphate in acidic medium, a dark brown ring was formed whereas on treatment with neutral FeCl3, it gave deep red colour which disappeared on boiling and a brown red ppt was formed. The mixture contains
MEDIUM
Consider the following reactions:
NaCl+K2Cr2O7+H2SO4Conc.A+ side products
A+NaOHB+ side products
B+H2SO4dilute+H2O2C+ side products
The sum of the total number of atoms in one molecule each of A,B and C is ________
EASY
Reaction of an inorganic sulphite X with dilute H2SO4 generated compound Y. Reaction of Y with NaOH gives X. Further, the reaction of X with Y and water affords compound Z, Y and X, respectively, are :
MEDIUM
Sodium nitroprusside, when added to an alkaline solution of sulphide ions, produce a
MEDIUM
A chloride salt solution acidified with dil. HNO3  gives a curdy white precipitate, [A], on addition of AgNO3. [A] on treatment with NH4OH gives a clear solution, B.
EASY
When treated with conc. HCl, MnO2 yields gas (X) which further reacts with Ca(OH)2 to generate a white solid (Y) reacts with dil. HCl to produce the same gas X. the solid Y is
HARD
The reagent(s) that can selectively precipitate S2- from a mixture of S2- and SO42- in aqueous solution is (are)
MEDIUM
A white sodium salt dissolves readily in water to give a solution which is neutral to litmus. When silver nitrate solution is added to the before mentioned solution, a white precipitate is obtained which does not dissolve in dilute nitric acid. The anion is:
EASY

The blue colour produced when a starch solution is added to a solution containing traces of I2 and KI is due to

(I) formation of I3-

(II) formation of an inclusion complex

(III) Oxidation of starch

(IV) Oxidation of I2

HARD
When a mixture of NaCl,K2Cr2O7 and concentrated H2SO4 is heated in a dry test tube, a red vapour X is evolved. This vapour X turns an aqueous solution of NaOH yellow due to the formation of Y. X and Y, respectively, are:
MEDIUM
HgCl2 and I2 both when dissolved in water containing I- ions the pair of species formed is:
MEDIUM
The sodium salt of an organic acid X produces effervescence with concentrated H2SO4. X reacts with the acidified aqueous CaCl2 solution to give a white precipitate which decolourises acidic solution of KMnO4. X is
HARD
Consider the following statements and arrange in the order of true/false for the given statements respectively.

 

S1: Like CO32,SO32 ions also give test with baryta water, Ba(OH)2.

S2:Ag2S is insoluble in hot and concentrated HNO3.

S3: Triodide ions (I3) produced by the reaction of Cu2+ and KI solution are not reduced by excess of sodium thiosulphate solution.

S4: Black precipitate of Cu(SCN)2 turns into white precipitate when it reacts with saturated solution of SO2 in water.