Fundamental Concepts of ChemistryPhysical Changes2726Choose the best answerA physical change is one in which:AChemical composition changesBPhysical state or another physical property may changeCNew chemical substances are always formedDChemical bonds must always be broken Like 0 Discuss 0Share
Chemical BondingBond Length2727Choose the best answerThe correct increasing order of bond length is:AC–H < C=C < C–O < C–CBC–H < C–O < C=C < C–CCC=C < C–H < C–O < C–CDC–H < C=C < C–C < C–O Like 1 Discuss 0Share
Carboxylic AcidsAcid Strength and pKa2728Choose the best answerWhich of the following is the strongest acid?AHCOOH, pKa = 3.77BC₆H₅COOH, pKa = 4.22CCH₃COOH, pKa = 4.71DCH₃CH₂COOH, pKa = 4.88 Like 0 Discuss 0Share
StoichiometryLimiting Reagent2729Choose the best answerFor the reaction: A + 2B → AB₂ 5 mol A and 2 mol B are mixed. Which is the limiting reagent?AABBCAB₂DCannot be determined Like 0 Discuss 0Share
UHS MDCAT 2023 ChemistryUHS MDCAT 2023 Past Paper#Electron Affinity#Periodic Trends2730Choose the best answerWhy is the electron affinity of fluorine lower than that of chlorine? (UHS MDCAT 2023)AFluorine has low electronegativityBIts small 2p shell has greater electron–electron repulsionCFluorine has fewer valence electronsDFluorine has a larger atomic size Like 0 Discuss 0Share