NEET Chemistry Questions: Purification and Characteristics of Organic Compounds

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In an organic compound , phosphorous in estimated as




In an organic compound, phosphorus is often estimated as magnesium pyrophosphate ( ext{Mg}_2 ext{P}_2 ext{O}_7). This compound is formed during the process of phosphorus analysis, where the organic sample is typically combusted, and the phosphorus is precipitated and weighed as magnesium pyrophosphate.
Which of the following is a technique of purification of organic compound ?




Distillation is a technique of purification of organic compounds. It involves heating a liquid to create vapor and then condensing the vapor back into a liquid. This method is commonly used to separate mixtures based on differences in their boiling points.
Which of the following is/are method (s) of checking the purity of organic compound ?




Both chromatography and spectroscopy are methods used to check the purity of organic compounds. Chromatography separates components of a mixture based on their movement through a stationary phase, while spectroscopy analyzes the interaction of light with the sample to identify and quantify the compounds present.
What is called the purification technique based on difference in the solubilities of the compound and the impurities in a given solvent ?




Crystallization is a purification technique based on the difference in the solubilities of the compound and the impurities in a given solvent. During crystallization, the desired compound forms solid crystals from a solution, leaving impurities in the solution.
What should be the property of solvent used in crystallisation ?




For effective crystallization, the solvent should exhibit two main properties: the impure compound should be sparingly soluble in it at room temperature and appreciably soluble at higher temperatures. This ensures that upon cooling, the pure compound crystallizes out, leaving impurities in the solution.
Which method of purification of organic compound is useful to separate liquids having sufficient difference in their boiling point ?




Distillation is useful for separating liquids with a significant difference in their boiling points. This method relies on heating the mixture to vaporize the more volatile component, which is then condensed back into a liquid in a separate container.
Which of the following method can be empolyed to separate a mixture of Chloroform (b.p334k) and aniline (b.p 457k) ?




To separate a mixture of chloroform (b.p 334K) and aniline (b.p 457K), distillation can be used. The substantial difference in boiling points allows for effective separation by selectively boiling and condensing each component.
Insulin contains 3.4% Sulphur. The minimum molecular weight of insulin is




To find the minimum molecular weight of insulin, we use the percentage of sulfur present. Given that insulin contains 3.4% sulfur, we assume the presence of one sulfur atom in the smallest unit of insulin. The atomic weight of sulfur is approximately 32 g/mol. Let's denote the minimum molecular weight of insulin as M. The percentage of sulfur can be expressed as (32/M) * 100% = 3.4%. Solving for M, we have M = (32 * 100) / 3.4 = 941.18. Since 941.18 is closest to option 940, the minimum molecular weight of insulin is approximately 940.
Which element is estimated by Carius method ?




The Carius method is used for the quantitative determination of halogens (chlorine, bromine, and iodine), sulfur, and phosphorus in organic compounds. The organic compound is heated with fuming nitric acid in a sealed tube, resulting in the formation of silver halide (if halogens are present) which can be weighted. Therefore, the element estimated by the Carius method is Halogen.
Distillation under reduced pressure is used when ...




Distillation under reduced pressure is used when a liquid has a very high boiling point and decomposes at or below its boiling point. The reduced pressure lowers the boiling point of the liquid, allowing it to be distilled without decomposition.
In Carius method, 0.099 g compound gave 0.287 gm AgCl. What is the % of Cl ?




$ \% Cl = { 35.5 \over 143.5 } \times { 0.287 \over 0.099} \times 100 $
In which compound, sulphur of organic compound is converted when organic compound is reacted with con. HNO3 for estimation of Sulphur ?




When an organic compound containing sulfur is reacted with concentrated nitric acid (HNO3) for the estimation of sulfur, the sulfur is converted into sulfuric acid (H2SO4). This is due to the strong oxidizing nature of concentrated nitric acid, which oxidizes sulfur to its highest oxidation state in sulfuric acid.
Which of the following techniques is used to separate glycerol from spent-lye in soap industry ?




Glycerol can be separated from spent-lye in the soap industry using distillation under reduced pressure. This method is preferred because glycerol has a high boiling point, and reducing the pressure lowers the boiling point, allowing the separation to occur without decomposition.
Which method is used to separate aniline water mixture ?




Steam distillation is used to separate aniline from water. Aniline and water form a heterogeneous mixture that can be separated by steam distillation because aniline is steam volatile and immiscible with water.
Chromatography is used




Chromatography is a versatile technique used to separate mixtures, purify compounds, and test the purity of compounds. It involves the partitioning of components between a stationary phase and a mobile phase, allowing for effective separation and analysis.