This physics problem tests your understanding of fundamental physical laws and their applications. The step-by-step solution below breaks down the problem using relevant equations and physical reasoning.
ScanSolve AI Answer
3.1 The boiling point is the temperature at which the vapor pressure of a liquid equals the external atmospheric pressure. 3.2 The controlled variable for this investigation is the class of alcohol (primary alcohols) or the type of functional group (hydroxyl group, -OH). 3.3 The trend observed is that the boiling points of the alcohols increase as the number of carbon atoms in the chain increases. This is because as the carbon chain length increases, the total surface area available for intermolecular contact also increases. This leads to stronger London dispersion forces (a type of intermolecular force) between the alcohol molecules. More energy is therefore required to overcome these stronger intermolecular forces, resulting in a higher boiling point. 3.4 The vapour pressure of the alcohols will DECREASE with an increase in the number of carbon atoms. As the number of carbon atoms increases, the intermolecular forces (London dispersion forces) become stronger (as explained in 3.3). Stronger intermolecular forces mean that fewer molecules have enough kinetic energy to escape from the liquid phase into the gas phase at a given temperature. Consequently, the vapor pressure above the liquid decreases. 3.5 The IUPAC name of the primary alcohol with a boiling point of 108 °C is 2-methylpropan-1-ol. Explanation for QUESTION 3.5: The table shows that straight-chain primary alcohols with 3 carbons (propan-1-ol) have a boiling point of 98 °C, and those with 4 carbons (butan-1-ol) have a boiling point of 118 °C. The given boiling point of 108 °C falls between these two values. 2-methylpropan-1-ol is an isomer of butan-1-ol, meaning both have the same molecular formula (C_4H_10O) and thus similar molar masses. Both are also primary alcohols, capable of forming hydrogen bonds. However, 2-methylpropan-1-ol has a branched carbon chain, while butan-1-ol has a straight chain. Branching reduces the surface area available for intermolecular contact between molecules. This results in weaker London dispersion forces in 2-methylpropan-1-ol compared to butan-1-ol. Less energy is required to overcome these weaker forces, leading to a lower boiling point for 2-methylpropan-1-ol (108 °C) than for butan-1-ol (118 °C). That's 2 down. 3 left today — send the next one.