Q60 of 66 Page 154

In the following questions a statement of Assertion (A) followed by a statement of

Reason (R) is given. Choose the correct option out of the choices given below each question.


Assertion (A): Components of a mixture of red and blue inks can be separated by distributing the components between stationary and mobile phases in paper chromatography.


Reason (R): The coloured components of inks migrate at different rates because paper selectively retains different components according to the difference in their partition between the two phases.


(i) Both A and R are correct and R is the correct explanation of A.


(ii) Both A and R are correct but R is not the correct explanation of A.


(iii) Both A and R are not correct.


(iv)A is not correct but R is correct.


The chromatography paper is used in paper chromatography, contains water in it, which is the stationary phase, and the solvent used is as the mobile phase. A strip of chromatography paper spotted at the base with ink is suspended in a suitable solvent.

The two inks are spotted at the base of the paper strip, and is dipped into the mobile phase, as the solvent rises up the paper by capillary action and flows over the spot selectively the paper retains different components according to their affinity for the paper.
Hence,
the coloured components of inks migrate at different rates because paper selectively retains different components according to the difference in their partition between the two phases.


The assertion and reason both are correct and reason is correct explanation of the assertion.


Option (i) is correct answer.


More from this chapter

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58

In the following questions a statement of Assertion (A) followed by a statement of

Reason (R) is given. Choose the correct option out of the choices given below each question.


Assertion (A): All the carbon atoms in H2C = C = CH2 are sp2 hybridised


Reason (R): In this molecule all the carbon atoms are attached to each other by double bonds.


(i) Both A and R are correct and R is the correct explanation of A.


(ii) Both A and R are correct but R is not the correct explanation of A.


(iii) Both A and R are not correct.


(iv) A is not correct but R is correct.


59

In the following questions a statement of Assertion (A) followed by a statement of

Reason (R) is given. Choose the correct option out of the choices given below each question.


Assertion (A): Sulphur present in an organic compound can be estimated quantitatively by Carius method.


Reason (R): Sulphur is separated easily from other atoms in the molecule and gets precipitated as light yellow solid.


(i) Both A and R are correct and R is the correct explanation of A.


(ii) Both A and R are correct but R is not the correct explanation of A.


(iii) Both A and R are not correct.


(iv) A is not correct but R is correct.


61

What is meant by hybridisation? Compound CH2 = C = CH2 contains sp or sp2 hybridised carbon atoms. Will it be a planar molecule?

62

Benzoic acid is an organic compound. Its crude sample can be purified by crystallisation from hot water. What characteristic differences in the properties of benzoic acid and the impurity make this process of purification suitable?