Question

find the number of representative particles in 2.50 moles of iron.

Answer 1

In chemistry and physics, the Avogadro constant (symbols: L, NA) is defined as the number of constituent particles (usually atoms or molecules) in one mole of a given substance. It has dimensions of reciprocal mol and its value is equal to $6.02214129 \times 10^{23} \mathrm{~mol}^{-1}$. Changes in the SI units are proposed that will change the constant to exactly $6.02214 \times 10^{23}$ when it is expressed in the unit $\mathrm{mol}^{-1}$

So if it is $2.50\mathrm{mol}$ of iron, the number of particles is next:

$$\mathrm{N} = \mathrm{NA} \times \mathrm{n}, \text{where}$$

n is amount

NA is Avogadro constant

N is number of particles, so

$$\mathrm{N} = \mathrm{NA} \times \mathrm{n} = 6.02214 \times 10^{23} \times 2.50 = 1.50554 \times 10^{24}$$