Principles Related to Practical Chemistry

Which indicator is used in the titration of sodium hydroxide against oxalic acid and what is the colour change at the end point?

1. Phenolphthalein, pink to yellow
2. Alkaline KMnO4, colourless to pink
3. Phenolphthalein, colourless to pink
4. Methyl orange, yellow to pinkish red colour

A steam volatile organic compound which is immiscible with water has a boiling point of 250 C. During steam distillation, a mixture of this organic compound and water will boil :

1. above 100 C but below 250 C
2. above 250 C
3. at 250 C
4. close to but below 100 C

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

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

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

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

On complete combustion, 0.3 g of an organic compound gave 0.2 g of CO2 and 0.1 g of H2O. The percentage composition of carbon and hydrogen in the compound, respectively is:

1. 4.07% and 15.02%
2. 18.18% and 3.70%
3. 15.02% and 4.07%
4. 3.70% and 18.18%

In Lassaigne's extract of an organic compound, both nitrogen and sulphur are present, which gives blood red colour with Fe3+ due to the formation of-

1. NaSCN
2. [Fe(CN)5NOS]4-
3. [Fe(SCN)]2+
4. Fe4[Fe(CN)6]3 xH2O

The Kjeldahl's method for the estimation of nitrogen can be used to estimate the amount of nitrogen in which one of the following compounds?

1. [figure]
2. [figure]
3. [figure]
4. [figure]

Paper chromatography is an example of :

1. Partition chromatography
2. Thin layer chromatography
3. Column chromatography
4. Adsorption chromatography

The most suitable method of separation of 1 : 1 mixture of ortho and para-nitrophenols is

1. chromatography
2. crystallisation
3. steam distillation
4. sublimation.

In Dumas method for estimation of nitrogen, 0.25 g of an organic compound gave 40 mL of nitrogen collected at 300 K temperature and 725 mm pressure. If the aqueous tension at 300 K is 25 mm, the percentage of nitrogen in the compound is

1. 16.75
2. 15.76
3. 17.36
4. 18.20