BCH4024 Exam 1 Purich Questions & Answers 2023/2024

BCH4024 Exam 1 Purich Questions & Answers 2023/2024 Basic Structure of water - ANSWER--large dipole moment -very polar that interactions between H2O molecules are strong--high heat capacity -liquid water=H-bonds are relentlessly made and broken; thus a flickering collection of W5 structures, with extremely little W1 -each water molecule can form up to 4 H-bonds -liquid water has 3.4 H-bonds on average -ice has 4 H-bonds H-bond - ANSWER-stable interaction occurring when 2 EN atoms share one H atom Water readily forms Hydrogen bonds... - ANSWER--acid/base interaction (proton donor-electropositive region and proton acceptor-electronegative region) -the bond is stronger when all 3 atoms are aligned -H-bonding gives water so much stability that it must be heated to its BP (100 degrees C) to break all H-bonding interactions -linear H-bonds are stronger than bent H-bonds Key properties of water due to its structure - ANSWER--high heat capacity (allows us to maintain a stable body temp.) -high BP relative to its molecular weight -high viscosity relative to its molecular weight -strong interactions with ionic molecules -special interactions with nonpolar molecules Special Properties of water - ANSWER--Accessible melting point of Water -occurs in a temp. range that helps to sustain Life on earth -as water freezes, it expands, ripping plants apart, allowing C atoms to re-enter the Carbon cycle