Question

A sample of neon occupies a volume of 641 ml at STP. What will be the volume of the neon when the pressure is reduced to 93.3 kPa?

Answer 1

STP is defined as a temperature of 273.15 K (0 °C) and an absolute pressure of exactly 105 Pa (100 kPa)*
P1V1 = P2V2, V2 = P1V1 / P2
V2 = 100 kPa ∙ 641 ml / 93.3 kPa = 687 ml.