Avogrado's number, which is approximately 6.022 x 10^23, represents the number of representative particles (atoms, molecules, or ions) in one mole of a substance. Therefore, to determine the number of representative particles in 2.5 moles, we simply multiply Avogrado's number by 2.5:

Number of representative particles = (Avogrado's number) x (Number of moles)

= (6.022 x 10^23) x (2.5)

= 1.5055 x 10^24

So, there are approximately 1.5055 x 10^24 representative particles in 2.5 moles of a substance.