physical techniques 1 / 20Which application uses supercritical CO₂ as a solvent in extraction Decaffeination of coffee Extraction of ionic compounds Purification of table salt Distillation of ethanol 2 / 20Why is multiple extraction more efficient than a single extraction It follows the principle of "smaller volumes, higher recovery" It uses less solvent overall It prevents emulsion formation It works faster 3 / 20Which law quantitatively describes solvent extraction efficiency? Nernst Distribution Law Raoult’s Law Beer-Lambert Law Henry's law 4 / 20Which of the following pairs of solvents are immiscible? Water and ethanol Water and dichloromethane (DCM) Acetone and methanol Hexane and toluene 5 / 20What is the purpose of a "salting-out" agent in solvent extraction? To increase the pH of the aqueous phase To reduce the solubility of the solute in the aqueous phase To emulsify the two phases To increase the boiling point of the solvent 6 / 20What is the role of a "mother liquor" in crystallization? The residual liquid after crystals form A solvent used for dissolving metals A catalyst for crystallization A type of seed crystal 7 / 20What is the key difference between crystallization and precipitation Crystallization is faster Crystallization forms ordered structures; precipitation forms amorphous solids Precipitation requires heating Only crystallization uses a solvent 8 / 20Crystallization is a type of Chemical reaction Physical separation technique Decomposition process Redox reaction 9 / 20What is a "seed crystal" used for To dissolve the solute faster To initiate controlled crystallization To change the solvent’s color To cool the solution 10 / 20Which solvent is commonly used for organic compound crystallization? Water Ethanol Mercury Sulfuric acid 11 / 20The shape of crystals depends mainly on: The molecular structure of the solute Color of solvent The container’s shape Atmospheric pressure 12 / 20Which compound is commonly purified by crystallization in labs Sand Copper sulfate (CuSO₄) Iron filings Charcoal 13 / 20Slow cooling of a solution generally produces Small, impure crystals Large, pure crystals Amorphous solids No crystals 14 / 20 Which of the following is NOT a method to induce crystallization Cooling a hot saturated solution Adding a seed crystal Boiling off all the solvent Scratching the container 15 / 20 The process of forming crystals from a supersaturated solution is called Evaporation Nucleation Distillation Sublimation 16 / 20 What is the primary purpose of crystallization To melt a solid To dissolve a solute completely To purify a solid substance To increase solubility 17 / 20 Which factor does NOT affect the rate of sublimation Temperature Surface area Density of the liquid phase Pressure 18 / 20The reverse process of sublimation is called Evaporation Condensation Deposition Freezing 19 / 20Which of the following substances sublimes at room temperature Water Iodine salt wax 20 / 20Riboflavin is also known as: A) Vitamin B1 B) Vitamin B2 C) Vitamin B3 D) Vitamin B6 Your score isThe average score is 83% 0% Restart quiz
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