Basic Concepts of ChemistryPhysical and Chemical Changes256Choose the best answerWhich of the following is an example of a chemical change?AMelting of iceBSwitching on a bulbCCutting fruit into piecesDRusting of iron Like 0 Discuss 0Share
Industrial ChemistryThermoplastic Polymers257Choose the best answerWhich statement correctly describes a thermoplastic polymer?AIt permanently decomposes whenever heated.BIt softens on heating and hardens on cooling, allowing reshaping.CIt always has a highly cross-linked three-dimensional structure.DIt cannot be reshaped after first formation. Like 0 Discuss 0Share
Chemical BondingMolecular Geometry and Bond Angle258Choose the best answerThe shape and bond angle of BF₃ are:ATrigonal pyramidal, 107°BTetrahedral, 109.5°CTrigonal planar, 120°DTrigonal pyramidal, 120° Like 0 Discuss 0Share
Stoichiometry Stoichiometry MCQS#Atomic Structure#Isotopes259Choose the best answerWhich statement correctly links atomic mass in amu with isotopes?Aamu ignores isotopes.Bamu depends on only one isotope of each element.CAtomic mass in amu reflects the weighted contribution of all naturally occurring isotopes.Damu is calculated using only neutrons. Like 0 Discuss 0Share
Chemistry of HydrocarbonsGeometrical Isomerism and Alkene Stability260Choose the best answerBetween cis-2-butene and trans-2-butene, the more stable isomer is:Acis-2-ButeneBtrans-2-ButeneCBoth are equally stableDcis-2-Butene only at all temperatures Like 1 Discuss 0Share