Assertion (A) : Sulphur present in an organic compound can be estimatedquantitatively by the Carius method.Reason (R) : Sulphur is separated easily from other atoms in the moleculeand gets precipitated as light yellow solid

Assertion (A) is correct. The Carius method is a well-known procedure used for the quantitative determination of halogens, nitrogen, and sulfur in an organic compound. The organic compound is heated with fuming nitric acid in the presence of silver nitrate contained in a hard glass tube known as a Carius tube. The sulfur in the compound is oxidized to sulfuric acid which then reacts with silver nitrate to form silver sulfate. The mass of the silver sulfate is then used to calculate the amount of sulfur in the original compound.

Reason (R) is also correct but it does not explain Assertion (A). While it's true that sulfur gets precipitated as a light yellow solid (silver sulfate), this is not the reason why sulfur can be estimated quantitatively by the Carius method. The reason is that the Carius method allows for the complete conversion of sulfur in the organic compound to a measurable form (silver sulfate), not the ease of sulfur's separation or its color. Therefore, Assertion (A) and Reason (R) are both correct, but Reason (R) is not the correct explanation for Assertion (A).