Created by Sana KaussarGravimetric and Chromatography Quiz Batch 08Gravimetric Analysis determines the mass of an analyte by converting it into a stable, weighable form. Chromatography separates and identifies components in a mixture based on their movement through a stationary phase. 1 / 50Which of the following types of compounds are best analyzed using Gas Chromatography Non-volatile compounds Large proteins Volatile and thermally stable compounds Highly polar, ionic compounds 2 / 50Which filter medium is used for high-temperature ignition in gravimetric analysis Filter paper Sintered glass crucible Gooch crucible (with asbestos) Membrane filter 3 / 50Which of the following is determined by volatilization gravimetry Chloride Water of crystallization Sulfate Iron 4 / 50Which industry benefits from gravimetric analysis Pharmaceutical mining Environmental science all 5 / 50The precipitate in gravimetric analysis should be Highly soluble Easily filterable Unstable Non-stoichiometric 6 / 50Which gel type is preferred for DNA separation Polyacrylamide Starch Agarose polyvinyl 7 / 50What is the role of a guard column in GC To separate compounds To protect the analytical column from contaminants To increase retention time to cool the sample 8 / 50In gas chromatography (GC), the mobile phase is solid inert gas liquid A supercritical fluid 9 / 50The purpose of using a coagulating agent (e.g., electrolyte) in gravimetric analysis is to Increase solubility of the precipitate Reduce particle size Promote coagulation for easier filtration Change the color of the precipitate 10 / 50The ideal precipitate in gravimetric analysis should Be highly soluble Have a large surface area Form colloidal suspensions Have a well-defined chemical composition 11 / 50In paper chromatography, what is the primary force that helps separate components Gravity Capillary action Centrifugal force Electromagnetic force 12 / 50In column chromatography, the elution order of compounds depends on Their boiling points Their polarity and interaction with the stationary phase Their molecular weight only Their color 13 / 50Increasing the column temperature in GC generally Increases retention times Decreases peak resolution Reduces analysis time but may lower resolution Has no effect on elution 14 / 50In TLC, which type of compound typically moves the farthest up the plate? Polar compounds Non Polar compounds Ionic compounds Amphoteric compounds 15 / 50Digestion of a precipitate helps in Increasing particle size and purity Decreasing particle size Dissolving the precipitate completely Making the precipitate more soluble 16 / 50Which injection method is used for analyzing thermally unstable compounds in GC? Split injection Splitless injection On-column injection Flash vaporization 17 / 50Electrophoresis separates molecules based on Size and charge Boiling point Refractive index Optical activity 18 / 50. What is the effect of increasing the column temperature in GC Decreases retention time Increases retention time Increases peak broadening Does not affect separation 19 / 50What is the typical mobile phase used in ion-exchange chromatography Organic solvents Aqueous buffer solutions Non-polar gases Supercritical fluids 20 / 50Why is pencil used instead of ink to draw the baseline in paper chromatography? Pencil marks do not dissolve in the solvent Pencil marks are easier to erase Pencil reacts with the solvent Ink improves the separation process 21 / 50The stationary phase in chromatography can be A liquid or a solid Only a gas Only a liquid Only a solid 22 / 50In the determination of Ba²⁺ as BaSO₄, the gravimetric factor is BaSO₄/Ba Ba/BaSO₄ SO₄/BaSO₄ Ba/SO₄ 23 / 50Which detector is commonly used in gas chromatography (GC) UV-Vis detector Flame ionization detector (FID) Refractive index detector Mass spectrometer (MS) 24 / 50Peptization is the process where A precipitate becomes colloidal A precipitate becomes crystalline A precipitate dissolves completely A precipitate changes color 25 / 50Gravimetric analysis is most suitable for Trace analysis Macro-level quantitative analysis Qualitative analysis Volatile compounds 26 / 50Discoverer of chromatography michael tswett Henry Richard walliam watson John crick 27 / 50The term "Rf value" in chromatography refers to Retention factor Refractive index Reaction rate Resolution factor 28 / 50Which of the following samples is LEAST suitable for GC analysis? Volatile organic compounds (VOCs) Thermally stable pesticides High-molecular-weight proteins Essential oils 29 / 50Which of the following solvents would likely move a polar compound faster in paper chromatography Water ethanol hexane acetone 30 / 50The washing solution for a precipitate should Dissolve the precipitate Remove impurities without peptization Increase particle size Change the precipitate color 31 / 50A capillary column in GC typically has A packed solid stationary phase A thin liquid stationary phase coated on the inner wall A length of less than 1 meter An internal diameter > 5 mm 32 / 50What is the formula for calculating the Rf value Distance traveled by solvent / Distance traveled by solute Distance traveled by solute / Distance traveled by solvent Distance traveled by solute × Distance traveled by solvent Distance traveled by solvent – Distance traveled by solute 33 / 50What is the primary reason for using a mixture of solvents in the mobile phase To increase the speed of separation To dissolve different components with varying polarities To decrease the Rf values of all compounds To prevent the paper from dissolving 34 / 50. Which detector is the most sensitive for detecting organic compounds in GC? Flame Ionization Detector (FID) Thermal Conductivity Detector (TCD) Electron Capture Detector (ECD) UV-Vis Detector 35 / 50Which of the following is NOT a common application of paper chromatography Identifying plant pigments Separating amino acids Analyzing hydrocarbons in petroleum Detecting drugs in biological samples 36 / 50Gravimetric analysis is based on the measurement of Volume of a solution Mass of a precipitate Color intensity Electrical conductivity 37 / 50Coprecipitation errors in gravimetric analysis can be minimized by Rapid precipitation Digestion of the precipitate Washing the precipitate thoroughly All of the above 38 / 50Which of the following precipitating agents is used for nickel determination as Ni(DMG)₂? Dimethylglyoxime Silver nitrate Barium chloride Ammonium hydroxide 39 / 50Locating reagent used for phonols is ninhydrin 10% H2SO4 FeCl3 chromate solution 40 / 50Which resin type is most suitable for strong anion exchange chromatography Sulfonic acid resins Carboxyl resins Quaternary ammonium resins Hydroxylated silica resins 41 / 50The solubility product (Ksp) of a precipitate is important because it determines The ignition temperature The completeness of precipitation The color of the precipitate The filterability 42 / 50The process of heating a precipitate to remove moisture and other volatile impurities is called: Filtration Ignition Dissolution Precipitation 43 / 50Electrogravimetry involves Precipitation by an electric current Filtration under vacuum Volatilization of the analyte Complexometric titration 44 / 50Occlusion in gravimetric analysis refers to Loss of precipitate during filtration Trapping of impurities within the precipitate Dissolution of the precipitate Formation of colloidal particles 45 / 50Which compound is commonly used to determine sulfate (SO₄²⁻) gravimetrically? AgNo3 BaCl2 NaOH HCl 46 / 50The mobile phase in paper chromatography is usually A solid adsorbent A liquid solvent A gas An ion-exchange resin 47 / 50The retention time in GC is defined as Time taken for the solvent front to elute Time between injection and detection of a peak’s maximum Time required to equilibrate the column Total run time of the analysis 48 / 50A tailing peak in GC is often caused by Too low column temperature Active sites in the column or contamination Excessive carrier gas flow Use of a capillary column 49 / 50A typical application of ion-exchange chromatography is Separation of amino acids Separation of volatile organic compounds Identification of fatty acids Thin-film coating 50 / 50Which of the following is a requirement for a successful gravimetric analysis? The precipitate must be soluble The precipitate must be of known composition The precipitate must be colored The precipitate must be volatile Your score isThe average score is 83% 0% Restart quiz
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