Principles Related to Practical Chemistry · Question 9

On heating, some solid substances change from solid to vapour state without passing through liquid state. The technique used for the purification of such solid substances based on the above principle is known as

1. Crystallization
2. Sublimation
3. Distillation
4. Chromatography

During the preparation of Mohr's salt solution (Ferrous ammonium sulphate), which of the following acid is added to prevent hydrolysis of Fe2+ ion?

1. dilute hydrochloric acid
2. concentrated sulphuric acid
3. dilute nitric acid
4. dilute sulphuric acid

Given below are certain cations. Using inorganic qualitative analysis, arrange them in increasing group number from 0 to VI. Choose the correct answer from the options given below.

1. B, A, D, C, E
2. B, C, A, D, E
3. E, C, D, B, A
4. E, A, B, C, D

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?

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