20 questions
Methods used for purification of organic compounds are based on:
A salt with few drops of conc. \( \text{HCl} \) gives apple green colour in flame test. The group precipitate of the salt is dissolved in acetic acid and treated with \( \text{K}_2\text{CrO}_4 \) to give yellow precipitate. When the sodium carbonate extract of the salt solution is heated with conc. \( \text{HNO}_3 \) and ammonium molybdate, it resulted a canary yellow precipitate. The cation and anion present in the salt are respectively,
Identify the incorrect statements regarding primary standard of titrimetric analysis.(A) It should be purely available in dry form.(B) It should not undergo chemical change in air.(C) It should be hygroscopic and should react with another chemical instantaneously and stoichiometrically.(D) It should be readily soluble in water.(E) \( \mathrm{KMnO}_4 \) & \( \mathrm{NaOH} \) can be used as primary standard.Choose the correct answer from the options given below:
Which one of the following set of elements can be detected using sodium fusion extract?
Given below are two statements:Statement I: Sodium dichromate and potassium dichromate are classified as primary standards in titrimetric analysis.Statement II: Phenolphthalein is a weak base, therefore it dissociates in acidic medium.In the light of the above statements, choose the correct answer from the options given below
\(A\) and \(B\) formed in the following reaction are: \( \mathrm{CrO_2Cl_2} + 4\,\mathrm{NaOH} \rightarrow A + 2\,\mathrm{NaCl} + 2\,\mathrm{H_2O} \)\( A + 2\,\mathrm{HCl} + 2\,\mathrm{H_2O_2} \rightarrow B + 3\,\mathrm{H_2O} \)
On heating a mixture of common salt and \( \text{K}_{2}\text{Cr}_{2}\text{O}_{7} \) in equal amount along with concentrated \( \text{H}_{2}\text{SO}_{4} \) in a test tube, a gas is evolved. Formula of the gas evolved and oxidation state of the central metal atom in the gas respectively are:
Match List -I with List-II
Choose the correct answer from the options given below:
Consider three metal chlorides \( x \), \( y \) and \( z \), where \( x \) is water soluble at room temperature, \( y \) is sparingly soluble in water at room temperature and \( z \) is soluble in hot water. \( x \), \( y \) and \( z \) are respectively:
\( \mathrm{HA(aq)} \rightleftharpoons \mathrm{H^+(aq)} + \mathrm{A^{-}(aq)} \)The freezing point depression of a \( 0.1 \, \text{m} \) aqueous solution of a monobasic weak acid \( \mathrm{HA} \) is \( 0.20^\circ \text{C} \). The dissociation constant for the acid is: [Given: \( K_f(\mathrm{H_2O}) = 1.8 \, \text{K kg mol}^{-1} \), molality \( = \) molarity]
Match the LIST-I with LIST-II.
Which of the following nitrogen containing compound does not give Lassaigne’s test?
Match List-I with List-II.
Compounds that should not be used as primary standards in titrimetric analysis are:(A) \( \text Na_{2}Cr_2O_7 \)(B) Oxalic acid(C) \( \text{NaOH} \)(D) \( \text FeSO_4 . 6H_2O \)(E) Sodium tetraborateChoose the most appropriate answer from the options given below:
The correct statement among the following, for a “chromatography” purification method is:
In sulphur estimation, \( 2.0 \times 10^{-3} \) mol of an organic compound \( (X) \) \( (\text{molar mass } 76 \, \text{g mol}^{-1}) \) gave \( 0.4813 \, \text{g} \) of barium sulphate \( (\text{molar mass } 233 \, \text{g mol}^{-1}) \). The percentage of sulphur in the compound \( (X) \) is ______ \( \times 10^{-1}\% \).(Nearest integer)
Given below are two statements:Statement I : Retardation factor ($R_f$) can be measured in meter / centimeter. Statement II :$R_f$ value of a compound remain constant in all solvents.
Choose the most appropriate answer from the options given below:
Match List-I with List-II.Choose the correct answer from the options given below:
