Final answer:
A 2 NaCl solution has double the ion concentration of a 1 NaCl solution, leading to higher electrical conductivity and noticeable differences in colligative properties.
Step-by-step explanation:
The comparison between a 2 M NaCl solution and a 1 M NaCl solution lies in the concentration of the sodium ions (Na+) and chloride ions (Cl–). When 2 moles of NaCl are dissolved, it results in 2 M Na+ and 2 M Cl–, because NaCl dissociates into one Na+ and one Cl– for each mole. In contrast, in a 1 M NaCl solution, there would be 1 M Na+ and 1 M Cl– ions in the solution. Thus, a 2 NaCl solution has double the ion concentration compared to a 1 NaCl solution, which has implications such as higher electrical conductivity and differences in colligative properties like vapor pressure lowering and osmolarity.