A) Methanol B) Water C) Carbon dioxide D) Acetone
A) Gas B) Solid C) Liquid D) Supercritical
A) Differences in boiling point B) Differences in molecular weight C) Differences in solubility in the mobile phase D) Differences in conductivity
A) Maintain supercritical conditions B) Avoid solvent contamination C) Increase column temperature D) Enhance detector sensitivity
A) Higher resolution B) Lower equipment cost C) Limited application range D) Faster separation
A) Enhances analyte solubility B) Stabilizes column efficiency C) Improves stationary phase selectivity D) Reduces detector interference
A) Transition zone B) Critical point C) Near-critical region D) Supercritical zone
A) Aqueous B) Solid C) Gas D) Liquid
A) Through exposure to light. B) By adding impurities. C) By altering its chemical composition. D) By changing the pressure and temperature, allowing fine-tuning between liquid-like and gas-like states.
A) Only when both components have identical critical points. B) When one component is much more volatile than the other, at high pressure and temperatures above the component critical points. C) At low pressures regardless of temperature. D) In all binary mixtures without exception.
A) Using only the critical temperature of one component. B) By summing the critical points of each component. C) As the arithmetic mean of the critical temperatures and pressures of the two components. D) It cannot be estimated; it must always be measured experimentally.
A) Equations of state, such as the Peng–Robinson or group-contribution methods. B) Through direct measurement at all possible pressures and temperatures. C) Using only empirical observations without calculations. D) By averaging the boiling points of the components.
A) The critical point B) The density-pressure line C) The boiling curve D) The melting curve
A) 7.38 MPa (73.8 bar) B) 3.4 MPa (34 bar) C) 40 bar D) 570 MPa
A) The density remains constant B) The density decreases significantly C) The density becomes higher D) The density fluctuates unpredictably
A) 7.38 MPa (73.8 bar) B) 3.4 MPa (34 bar) C) 570 MPa D) 14,000 MPa
A) Michael Faraday B) Benjamin Thompson C) James Prescott Joule D) Baron Charles Cagniard de la Tour
A) Cosmetics B) Food science C) Microelectronics D) Pharmaceuticals
A) 500 K B) 273 K C) 735 K D) 300 K
A) 12.0 megapascals B) 1.0 megapascal C) 5.0 megapascals D) 9.3 megapascals
A) Biomass gasification reactors. B) Supercritical fluid extraction equipment. C) Hydrogen production facilities. D) CO2-based dry cleaning equipment.
A) They increase reaction time. B) They are cheaper than conventional solvents. C) Rapid diffusion accelerates diffusion-controlled reactions. D) They eliminate the need for catalysts.
A) 100–10000 nm B) 5–2000 nm C) 10–5000 µm D) 50–500 nm
A) It speeds up the drying process significantly. B) It reduces the cost of materials used. C) It enhances the mechanical strength of the aerogel. D) It removes solvent without causing distortion due to surface tension.
A) It uses less energy to heat the water. B) It increases the volume of hydrogen produced. C) It eliminates bubbles on electrodes, reducing ohmic losses. D) It decreases the need for catalysts.
A) Lignin is completely converted into simple sugars. B) Aliphatic inter-ring linkages are cleaved into low molecular weight mixed phenols. C) Lignin forms a protective layer around polysaccharides. D) Lignin remains unchanged due to short reaction times.
A) Large amounts of water are needed to maintain the reaction. B) The process requires long reaction times to be effective. C) Supercritical conditions can only be achieved at low pressures. D) A continuous reaction system must be devised due to very short reaction times.
A) NH3, SO2, NOx B) H2, CH4, CO2, CO C) O2, N2, Ar D) Neon, Krypton, Xenon
A) Hydrogenation B) Transesterification C) Oxidation D) Fermentation
A) Otto cycle B) Rankine cycle C) Brayton cycle D) The Allam cycle
A) Reduced radiation exposure. B) Increased fuel availability. C) Similar thermal efficiency gains. D) Lower operational costs.
A) Sleipner gas field B) Texas gas field C) Alaska gas field D) North Sea gas field
A) Japan B) India C) South Korea D) China
A) Antimicrobial properties B) Enhanced conductivity C) Reduced density D) Increased viscosity |