LiquidsHydrogen Bonding in Biomolecules116Choose 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
LiquidsAnomalous Behaviour of Water117Choose 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
LiquidsIntermolecular Forces and Melting Point118Choose the best answerWater has a higher melting point than petrol mainly because water has:AWeaker intermolecular forcesBStronger intermolecular forcesCNo intermolecular forcesDLower molecular attraction Like 0 Discuss 0Share
LiquidsRelative Strength of Intermolecular Forces119Choose the best answerWhich is the strongest intermolecular force among the following?AHydrogen bondingBDipole-induced dipole forceCDipole–dipole forceDLondon dispersion force Like 0 Discuss 0Share
LiquidsHydrogen Bonding and Vapour Pressure120Choose the best answerHydrogen bonding lowers the vapour pressure most clearly in:AHClBHBrCHFDHI Like 0 Discuss 0Share