A chemist prepares a solution by mixing of NaCl(s) with of methanol, CH OH( )
CHEMISTRY · Multi-part · AP · Chemistry · Properties of Substances and Mixtures · Properties of Substances and Mixtures
Problem
A chemist prepares a solution by mixing 0.10mol of NaCl(s) with 500g of methanol, CH3OH(l). After vigorous stirring, all of the salt dissolves, and the beaker becomes noticeably warm.
(1) Part 1: List every distinct type of particle–particle interaction present in the final homogeneous solution. Specify the two species involved in each interaction.
(2) Part 2: Identify which single interaction from part (a) most directly accounts for the exothermic (warming) observation and justify your choice.
(3) Part 3: If the experiment were repeated with carbon tetrachloride, CCl4(l) substituted for methanol under otherwise identical conditions, predict whether the dissolution of NaCl would be endothermic, exothermic, or essentially non-occurring. Provide an explanation based on the intermolecular and ion–molecule interactions you expect.