MEDIUM
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Sodium carbonate extract is prepared by:

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Important Questions on Organic Chemistry - Some Basic Principles and Techniques

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
Match the organic compounds in column - I with the Lassaigne's test result in column - II appropriately:
 
  Column – I   Column - II
A. Aniline i. Red colour with FeCl3
B. Benzene sulfonic acid ii. Violet color with sodium nitroprusside
C. Thiourea iii. Blue color with and acidic solution of FeSO4
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:
EASY
The correct match between item I and item II is
 
Item I (Compound) Item II (Reagent)
a. Lysine p. 1-naphthol
b. Furfural q. Ninhydrin
c. Benzyl alcohol r. KMnO4
d. Styrene s. Ceric ammonium nitrate
EASY
Sodium extract is heated with concentrated HNO3 before testing for halogens because :
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
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
EASY
The reddish brown precipitate formed in the Fehling's test for aldehydes (RCHO) is due to the formation of
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:
MEDIUM
When nitrogen and chlorine containing organic compound is reacted with sodium metal, it forms
EASY
Which of the following compound will give blood red colour while doing the Lassaigne's test for N.
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