Which statement(s) explain(s) the trend in boiling points as the chain length of straight-chain alkanes increases?
1: The surface area of contact increases, resulting in stronger induced dipole-dipole interactions (London forces). 2: The C−C\text{C}-\text{C}C−C and C−H\text{C}-\text{H}C−H covalent bonds become stronger. 3: The molecules become more polar, leading to stronger permanent dipole-dipole interactions.
1, 2 and 3
Only 1 and 2
Only 2 and 3
Only 1
