LiquidsBoiling Point46Choose the best answerWhy does water have a much higher boiling point than hydrogen sulfide (H₂S)?AWater has a higher molar massBH₂S forms stronger covalent bondsCWater is less polarDWater molecules form strong hydrogen bonds Like 2 Discuss 0Share
LiquidsHydrogen Bonding in Biomolecules47Choose the best answerThe two strands of a DNA double helix are held together mainly by:AHydrogen bondingBIonic bondingCMetallic bondingDCovalent bonds between the two strands Like 0 Discuss 0Share
LiquidsBoiling Point and External Pressure48Choose the best answerIf the external pressure on a liquid is reduced from 760 mmHg to 50 mmHg, its boiling point will:ADecreaseBRemain unchangedCIncreaseDBecome independent of pressure Like 0 Discuss 0Share
LiquidsHeat of Vaporization and Intermolecular Forces49Choose the best answerLiquids with strong dipole–dipole attractions generally have:ANegligible heat of vaporizationBHigh heat of vaporizationCVery low heat of vaporizationDZero heat of vaporization Like 0 Discuss 0Share
LiquidsAnomalous Behaviour of Water50Choose the best answerWater becomes less dense when it freezes because:AAn open hydrogen-bonded structure containing empty spaces formsBIonic bonds are formedCO–H bonds disappearDMolecular mass decreases Like 0 Discuss 0Share