Principles Related to Practical Chemistry · Question 7

A paper dipped in a dil. H2SO4 solution of 'X' upon treatment with SO2 gas turns into green. The compound 'X' is :

1. KI-starch
2. KMnO4
3. Pb(CH3COO)2
4. K2Cr2O7

Identify the colour of compound 'X' in the sequence of the reaction. [figure]

1. Violet
2. Green
3. Red
4. Colourless

2.0 g of a bromo hydrocarbon (X) was subjected to Carius analysis, gave 3.36 g of AgBr. The percentage of carbon in the compound (X) is 26.7%. Total number of carbon atoms in the empirical formula for compound (X) is . (Given molar mass in g mol-1 H : 1, C : 12, Br : 80, Ag : 108)

Among Fe3+, Pb2+, Cu2+ and Mn2+, identify the one that gets precipitated out while passing H2S in presence of NH4OH as group reagent. The highest possible oxidation state of the corresponding metal is

1. +3
2. +4
3. +2
4. +7

Match the LIST-I with LIST-II Choose the correct answer from the options given below:

1. A-III, B-I, C-IV, D-II
2. A-III, B-IV, C-I, D-II
3. A-I, B-III, C-II, D-IV
4. A-I, B-II, C-III, D-IV

In sulphur estimation, 2.0 10-3 mol of an organic compound (X) (molar mass 76 g mol-1) gave 0.4813 g of barium sulphate (molar mass 233 g mol-1). The percentage of sulphur in the compound (X) is 10-1 % (Nearest integer)

Given below are two statements : In the light of the above statements, choose the correct answer from the options given below :

1. Both Statement I and Statement II are true
2. Both Statement I and Statement II are false
3. Statement I is true but Statement II is false
4. Statement I is false but Statement II is true

Match List - I with List - II.

1. A-IV, B-II, C-I, D-III
2. A-IV, B-II, C-III, D-I
3. A-II, B-IV, C-I, D-III
4. A-II, B-IV, C-III, D-I

A salt with few drops of conc. HCl gives apple green colour in flame test. The group precipitate of the salt is dissolved in acetic acid and treated with K2CrO4 to give yellow precipitate. When the sodium carbonate extract of the salt solution is heated with conc. HNO3 and ammonium molybdate, it resulted a canary yellow precipitate. The cation and anion present in the salt are respectively,

1. Ca2+ and SO42-
2. Ba2+ and PO43-
3. Mn2+ and PO43-
4. Ba2+ and SO42-

Complete combustion of X g of an organic compound gave 0.25 g of CO2 and 0.12 g of H2O. If the % of carbon is 25% and of hydrogen is 4.89%, then X = 10-3 g. (Nearest integer) (Molar mass of C, H and O are 12, 1 and 16 g mol-1 respectively.)

1. 273
2. 27
3. 2730
4. 227