Which of the following will most accurately measure 500mL of solution?

The 500-mL volumetric flask is designed specifically for measuring accurate volumes of liquid, making it the most precise choice for measuring a 500 mL solution. Volumetric flasks have a wide base and a narrow neck, allowing for precision in filling to the calibration mark, which is ideal for applications where exact measurements are crucial, such as in titrations or when preparing standard solutions.

In contrast, while beakers, Erlenmeyer flasks, and graduated cylinders can hold 500 mL, they do not offer the same level of accuracy. Beakers and Erlenmeyer flasks are more suited for mixing and are generally not calibrated for precise volumes. They might have graduated markings, but these are not as precise as the calibration of a volumetric flask. Graduated cylinders provide better accuracy than beakers and Erlenmeyer flasks due to their design, but they still cannot match the precision of a volumetric flask, especially at specific volumes like 500 mL.